A quick recap: PSG looked seriouusly out of sorts during a first half in which their visitors from Spain looked dangerous but stepped up their game after the break.

With Real Sociedad defender Hamari Traore off the pitch after receiving treatment for an injury, Kylian Mbappe took advantage of his marker’s absence to fire his side ahead at a corner just before the hour. Bradley Barcola doubled PSG’s lead with a neat solo effort 12 minutes later.

It’s still all to play for in the second leg but one suspects that not even a team as flaky as PSG will blow this … actually, let’s not jump to any hasty or premature conlcusions.

90+3 min: PSG dominate possession in time added on, leaving La Real to chase shadows as the clock ticks down.

90+1 min: Hamari Traore is booked for an agricultural challenge on Fabian Ruiz, who drops like a sack of spuds.

90 min: We’ll have a minimum of four minutes of added time.

89 min: Real Sociedad win a corner. They take it short to Kubo, who squares the ball from the edge of the PSG penalty area. John Pacheo can’t get a clean shot away and sends the ball over the bar.

87 min: Kolo Muani selfishly pulls the ball wide wide from a tight angle when he had Mbappe and Hakimi up in support at the end of a promising counter-attack set in motion by Marco Asensio.

85 min: Kubo, who was so busy on behalf of La Real in the opening 45 minutes, gets a rare touch in this second half. He is immediately crowded off the ball.

84 min: With a shimmy here, several stepovers there and a drag-back or two thrown in for good measure, Kylian Mbappe tries to get a cross in towards Asensio at the far post but succeeds only in winning his team a corner. Nothing comes of it.

81 min: Second-half Sociedad have looked a pale facsimile of first-half Sociedad and have been punished accordingly. They’ll do well to escape Paris with just a 2-0 deficit to overturn in the second leg. PSG substitution: Ousmane Dembele is replaced by Randal Kolo Muani.

79 min: Real Sociedad triple-substitution: John Pacheo, Benat Turrientez and Umar Sadiq on for Le Normand, Mendez and Silva.

78 min: Lucas Hernandez is also on for PSG, having replaced Danilo.

77 min: PSG break upfield with Dembele on the ball with Mbappe and Marco Asensio, who is on for Barcola, in support. He fails to pick out either man.

75 min: PSG are now in comp-lete control of this game, with the players of Real Sociedad looking as fatigued as they are dispirited. They’re struggling to get the ball out of their own half now that PSG have wrestled control of midfield and got themselves a two-goal lead.

73 min: Fabian Ruiz plays the ball to Kylian Mbappe’s feet in the Real Sociedad penalty area. He’s unable to contorl it properly under pressure from a defender and can only scuff a shot well wide.

68 min: Kylian Mbappe bears down on the Real Sociedad penalty area, with Dembele charging into the box looking for the pass. Mbappe goes it alone and shoots from distance but his effort is high over the bar.

66 min: Real Sociedad substitution: Arsen Zakharyan on for Ander Barrentxea.

64 min: Kylian Mbappe shoots venomously from the edge of the Real Sociedad penalty area. Alex Remiro does superbly to tip the rising drive on to the bar and out for a corner.

61 min: It’s worth noting that PSG scored their goal when Hamari Traore was off the pitch, waiting to be allowed back on after receiving treatment for a knee injury. What’s more, Kylian Mbappe was unmarked as he steered the ball goalwards from Marquinhos’ flick-on. You can make of that what you will.

60 min: Their tails up, PSG get forward again. Achraf Hakimi drills a low cross into the Real Sociedad penalty area and it’s put out for another corner. Nothing comes of this one.

56 min: Mbappe has a shot-cross deflected out for a PSG corner. Before it can be taken, there’s a break in play as Real Sociedad right-back Hamari Traore receives treatment for an injury in his own penalty area. Moments previously, his goalkeeper Alex Remiro had saved a half-chance from a narrow angle at the feet of Barcola.

55 min: Mbappe receives a pass on the edge of the Real Sociedad penalty area, shimmies left and right, then gives the ball away.

52 min: Lucas Beraldo advances upfield for PSG, who look as pedastrian in the early stages of this second half as they did throughout most of the first. Luis Enrique must be consideirng changes as the Parisienne crowd are understandably unhappy with what they’re seeing and are whistling their discontent.

49 min: Achraf Hakimi sends a low cross fizzing into the Real Sociedad penalty area and Mbappe hits it first time. His shot has the sting taken out of it by a deflection off Igor Zubeldia and the ball trundles into the grasp of the crouching Alex Remiro.

49 min: Andre Silva tries to bring the ball down on the edge of the PSG penalty area but touches it with his hand and is penalised accordingly.

47 min: A lively presence on the right for La Real, Zubo cuts inside from the right again but runs into traffic and loses the ball.

46 min: PSG’s midfield trio of Warren Zaire-Emery, Fabian Ruiz and Vitinha have struggled in this game, finding it difficult to get the ball forward as they find themselves the subject of up-close-and-personal man-to-man marking from Brais Mendez, Martin Zubimendi and Mikel Merino.

45 min: Real Sociedad go close again, with Mikel Merino, their captain for the night, shooting from distance and beating Donnarumma, only to see his surface-to-air effort hit the bar.

44 min: The clock ticks towards half-time in a game that has thus far been reasonably entertaining. PSG haven’t offered a great deal apart from a few forays in behind Real Sociedad’s defensive line, while the visitors from San Sebastian have looked dangerous but far from lethal.

43 min: Real Sociedad striker Andre Silva tries his luck, attempting to score with an acrobatic bicycle kick. He doesn’t get near the ball but you can’t but applaud his ambition.

42 min: Kubo whips in another cross, this time from open play. Danilo gets a crucial touch before the ball can fizz across the face of the PSG goal.

39 min: Kubo gives Lucas Beraldo the slip and advances down the right wing. The Japanese international wins and takes a corner, which Donnarumma comes off his line to punch clear for PSG.

38 min: From the free-kick, Vitinha picks out Marquinhos at the far post and he heads the ball across the face of goal. Andre Silva is on hand to head it clear for Real Sociedad.

37 min: Robin Le Normand fouls Ousmane Dembele as he turns on the afterburners, then Mikel Merino sticks out a leg to help bring down the PSG winger. It’s a free-kick for PSG and a yellow card for Le Normand. Merino avoids a booking but did seem to hurt his shoulder as he fouled Dembele.

34 min: The ball’s sent into the penalty area, cleared and then lofted back towards the far post. Bradley Barcola has to react extremely quickly and can only head over the bar.

33 min: Kylian Mbappe takes the ball around Hamari Traore and advances towards the left side of the Real Sociedad penalty area. With Dembele screaming for a cross to the far post, Mbappe runs into traffic and has to settle for a corner.

30 min: Galloping up the right, Dembele is dispossessed on the touchline by Javi Galan, electing to hurdle the Real Sociedad left-back’s robust challenge and leave the ball behind him.

28 min: With almost half an hour gone, one suspects that Real Sociedad boss Imanol Alguacil will the happier of the two managers. His side have created the best chance of the game and are more than holding their own against their exalted opposition, although their high defensive line does look like an accident waiting to happen.

25 min: Just inside the Real Sociedad half, Ousmane Dembele latches on to a long ball from deep, gallops upfield and with Kylian Mbappe upsides him in support, goes it alone and shoots into the side-netting. The flag goes up for offside.

24 min: PSG get forward but a promising attack breaks down when Bradley Barcola fails to control a low pass out wide from Kylian Mbappe and lets the ball run out of play for a Real Sociedad throw-in.

22 min: Andre Silva stretches to get on the end of a Kubo cross and steer an excellent header from about 14 yards towards the far upright. Donnarumma looked beaten but watches in relief the ball drifts narrowly wide. That was a superb effort by the La Real striker, as the ball from Kubo was slightly behind him.

20 min: Real Sociedad win another free-kick in a promising area after Lucas Beraldo accidentally catches a rival with a stray elbow. Brais Mendez sends the ball into the PSG penalty area, where Danilo heads clear.

19 min: Real Sociedad corner. Kubo’s delivery to the near post is headed out of danger towards the far touchline by Vitinha.

18 min: Kubo picks up the ball on the right flank, then jinks this way and that before cutting inside on his left foot. He fails to get much power on his low shot and pulls the ball the wrong side of the near upright.

15 min: Real Sociedad free-kick on the inside right. Brais Mendez floats the ball to the far post, where Mikel Merino sidefoots it across the face of goal but Marquinhos gets a foot in before anyone in a blue and white striped shirt can poke home from close range. That was well worked free-kick and a wonderful opportunity for Real Sociedad to take the lead goes to waste.

14 min: Takefusa Kubo dithers on the ball and misses an opportunity to pick out Mikel Merino with a through ball.

12 min: PSG gift the ball to Real Sociedad twice in quick succession but the Basque side are unable to do much with it. On the first occasion, Ander Barrentxea made ground up the inside left but his attempt to pick out Andre Silva in a good position is intercepted by Danilo.

10 min: PSG enjoy a period of sustained possession without doing much of interest with it. Their players seem happy enough to just ping the ball about between themselves in the middle third of the pitch.

8 min: The ball’s played up the right flank for Takefusa Zubo to chase, but he’s unable to control it and PSG left-back Lucas Beraldo tidies up, passing back to his goalkeeper Giannluigi Donnarumma.

7 min: Kylian Mbappe is sent on his way in behind the Real Sociedad high defensive line. He finds himself one on one with Alex Remiro and brings a smart save out of the visiting goalkeeper. He should have scored.

5 min: The ball’s played wide to Bradley Barcola, who is hugging the left touchline, with Ousmane Dembele doing the same on the right. He’s unable to get a cross in.

4 min: PSG get forward but are unable to get the ball to Kylian Mbappe in the middle, despite the best attempts of Ousmane Dembele and Fabian Ruiz.

3 min: Real Sociedad haven’t come here to sit back and defend. They’re playing a high line and pressing ferociously.

Not long now: The pre-match light show has conluded and it’s time for our Italian referee Marco Guida and his team of match officials to lead both sets of players out on to the pitch, where they’ll line up for the Champions League anthem.

Paris Saint-Germain are hoping to avoid their third consecutive exit at this stage of the tournament, while Real Sociedad are hoping to make the quarter-finals for the first time in their history. It’s Valentine’s Day in the City of Love and kick-off is just a couple of minutes away.

Elsewhere in the Champions League: Lazio host Bayern Munich in tonight’s other Round of 16 first leg and you can follow the action from Rome with Niall McVeigh.

Lazio currently languish in eighth place in Serie A, while Bayern Munich are second in the Bundesliga and hoping to bounce back from their weekend defeat at the hands of unbeaten league leaders Bayer Leverkusen.

Kieran Tierney interview: Despite having his season on loan at Real Sociedad from Arsenal interrupted by a couple of hamstring injuries, the Glaswegian is having the time of his life in San Sebastian, where it seems he could not be happier. Words: Sid Lowe.

Luis Enrique: “I think that when a team has a player of Kylian Mbappe’s calibre, the only thing you have to understand is that the more he plays, the better it is for everyone,” said PSG’s manager, upon being asked about his striker’s availability.

“We all benefit, that’s our goal, there’s no doubt about that. He could have played four days ago if it had been a final, but since that wasn’t the case I don’t think the risk was worth it. So he’s available and he’s been training like the rest of the players.”

Enrique refused to entertain a question regarding the possibility that this could be Mbappe’s final Champions League game at Parc des Princes as a PSG player. “No,” he said. “That’s not how I feel about it.”

Form guide: Since scraping through to the knockout stages of the Champions League on goal difference courtesy of a 1-1 draw with Borussia Dortmund, Paris Saint-Germain are unbeaten in 10 games in all competitions and came from behind to beat Lille and open an 11-point gap at the top of Ligue 1 last time out. Luis Enrique’s side are currently on a 15-match unbeaten run but have gone of the Champions League to Spanish opposition in five of the past six seasons.

Currently sitting seventh in La Liga, nine points of the Champions League places, Real Sociedad’s form has been far less impressive since a scoreless draw at Inter ensured they finished top of Group D and advanced to the last 16. Imanol Alguacil’s side have struggled for any kind of consistency since then, winning four and drawing six of their 12 games in the interim. More worryingly, they have failed to trouble the scoreboard operator in any of their past four matches.