When Iliman Ndiaye walked off to a standing ovation in the 83rd minute with Everton two goals ahead, Sean Dyche may have expected similar treatment at the full-time whistle. Instead, he was greeted with a chorus of boos after three quickfire Bournemouth goals condemned the hosts to a third straight defeat to start the Premier League season.

On the day Everton remembered their legendary striker Kevin Campbell, Michael Keane and Dominic Calvert-Lewin had set them on their way to what looked like an almost certain victory. Then Antoine Semenyo, Lewis Cook and Luis Sinisterra, the last two coming in injury time, struck inside the six-yard box as Everton’s flaws were shown up. “I explain it by not doing the hard side of the game,” Dyche said. “I speak to the players all the time and that’s my biggest frustration since the moment I walked in here. I’ve always said to them: ‘Whatever you learn from me, the fact is the game lasts as long as the referee makes it last, so you have to play for every breath of the game.’”

It was supposed to be very different. Ndiaye had illuminated Goodison Park on the left wing, providing verve and style to a team anchored on workrate, and walked off thinking the job was done. Bournemouth were barely part of the fixture, struggling to keep the ball and hardly creating a chance in the first 87 minutes before three late crosses were diverted home.

Under Dyche, Everton are slow starters. Last season they picked up one point from their opening four matches. They prop up the table, having conceded 10 in three matches.

“It’s the most frustrating [defeat of my career] because to dominate a game for that long and play so well and then come out of it without something at least is incredibly frustrating, I will say that,” Dyche said. “As a manager, these are the ones you scratch your head at. Part of learning as a footballer is when you can smell it on the pitch while you’re active, not just the manager and the coaches, because we obviously can. We’re trying to give some information to correct it.”

For 86 minutes, Everton were the only team in the match. They had looked exciting going forward and Jordan Pickford had been a spectator, occasionally having to retrieve the ball from the fans after a wayward Bournemouth shot from distance. Ndiaye, Dwight McNeil and Jack Harrison were dynamic behind Calvert-Lewin, who took his goal expertly. Everton’s season had lift-off and Goodison Park was bouncing.

There was the old Dyche for the first goal as Harrison found Calvert-Lewin in the box, before he laid it off for Keane to thrash home. The second was out of a new playbook, a vibrant move as Ndiaye and McNeil combined on the edge of the box, allowing the latter to slip the ball through for Calvert-Lewin. It was the best of both worlds for Dyche.

Everton were undone by three crosses in the final stages, all prodded or headed home from close range. After Semenyo slid in the first from a Dango Ouattara cross, Dyche took off Calvert-Lewin and brought on Beto rather than making a defensive change. Most teams might not have been worried about seeing the match out but Everton panicked, the memories of their crushing losses against Brighton and Tottenham coming back.

“It’s always the manager that takes responsibility,” Dyche said. “You are looking for your team while they’re out there to take responsibility. But it takes character and it takes leadership and it takes people who’ve been around to smell it, almost.”

Cook nodded in the second from another cross to bring bedlam to those who had travelled for what looked like a miserable afternoon. Everything was coming from out wide and nothing was changed to stop the problem, resulting in Justin Kluivert finding Sinisterra in the 96th minute. Many fans were almost too shocked by what they had witnessed to make their feelings known but plenty remembered to show their disgust at the late collapse once the whistle went.

For Bournemouth they have their first win after two draws. “It is a very important win for us. I think it was the worst game we’ve played this season,” Andoni Iraola said. “We were the best team in the previous three but Everton were the best team today. I have to accept they deserved to win.” Iraola told Dyche the same. Not that it will bring him much comfort.