The red mist descended on the Amex Stadium as tempers reached boiling point in a fractious finale to this ill-tempered draw, which resulted in Morgan Gibbs-White and both managers being sent off. Nottingham Forest’s midfielder Gibbs-White was shown a second yellow card for a late challenge on the substitute João Pedro while Nuno Espírito Santo and Fabian Hürzeler were dismissed for their furious reactions on the touchline.

Chris Wood’s early penalty sparked hopes of a fifth successive away victory for Forest, on a run stretching back to the end of last season. Two Brighton goals at the end of the first half – a magnificent header from the teenager Jack Hinshelwood and Danny Welbeck’s curling free-kick – turned the contest on its head. The visitors rung the changes in the second half and were rewarded with an equaliser from the substitute Ramón Sosa to ensure both teams remain unbeaten.

Gibbs-White was controversially sent off for his challenge despite the referee, Rob Jones, initially appearing to wave play on. Nuno was enraged, presumably assuming the fourth official, Anthony Taylor, had influenced Jones by communicating from the touchline, and was shown a red card. Brighton’s manager Hürzeler was also ordered off.

Taylor was temporarily pulled from refereeing duties after social media abuse following his performance in handing out 14 yellow cards during Chelsea’s win at Bournemouth last week.

Andrew Crofts, Brighton’s first-team coach, said: “There is a tackle we felt was a foul. João Pedro was hurt and their player didn’t mean to hurt him but it was a foul. I didn’t hear too much so didn’t see what part he [Taylor] would have. I think he would have been in communication with the referee that he felt it was a foul.”

Rui Pedro Silva, the Forest assistant coach, said: “I’m always going to give my view from the bench. I thought it was a good and fair tackle. I saw nothing that justified a second yellow card. The referee took their time and made the final decision to show a second yellow.

“I didn’t hear anything from Nuno justifying the red card. It’s very emotional and you’re going to defend your player and your team.”

Brighton dominated the early possession and cut Forest open through Georginio Rutter’s threaded pass but Simon Adingra rolled their first attempt wide of Matz Sels’ far post. Forest’s first attack paid dividends when Callum Hudson-Odoi charged into the area following a direct run by Gibbs-White and Carlos Baleba clumsily brought the attacker down. Wood stepped up and sent the Brighton goalkeeper Bart Verbruggen the wrong way for his third league goal of the season.

Hudson-Odoi teed up Wood but the former Brighton striker fired wide from close range with the offside flag sparing his blushes. Forest threatened on the break with Hudson-Odoi – promoted to the team after his winner in last week’s shock victory at Liverpool – setting up Gibbs-White but the England midfielder shot straight at Verbruggen.

Rutter was looking the hosts’ most likely creator with the former Leeds forward blasting a shot wide from the edge of the area.

Brighton’s first effort on target was a significant one with their equaliser arriving before the break. Jan Paul van Hecke floated in a cross and Hinshelwood rose supremely to plant a header past the despairing dive of Sels. It got even better for Brighton as they quickly added a second through Welbeck’s free-kick, which curled round the wall past the motionless Sels with the keeper at fault.

Nuno acted at half-time with the introduction of Jota Silva, Neco Williams and Ryan Yates for James Ward-Prowse, Àlex Moreno and Anthony Elanga in an attempt to change the momentum of the match. The Paraguay forward Sosa was also brought on shortly afterwards to increase their attacking options.

Kaoru Mitoma was a menacing presence on the left wing for Brighton and his interplay with Welbeck kept Forest under pressure. Welbeck almost struck again after the restart, with the forward wriggling his way through the defence but Sels made a crucial save with his leg to deflect the ball behind for a corner.

Yankuba Minteh was brought on but the Brighton attacker’s first involvement was at the wrong end, with his backward header forcing Verbruggen to prevent an own goal.

Forest still carried a threat on the counterattack and two of their substitutes combined to snatch an equaliser midway through the half. Gibbs-White played an incisive pass through to Jota and he unselfishly laid the ball back for Sosa to score from close range for his first goal for the club.

There was still time, after the late drama involving Gibbs-White and the managers, for Sosa to waste a glorious opportunity on the break. Brighton had to settle for the fact that, for the first time, they remain unbeaten after their opening five matches of a top-flight season.