Baked by Easter sun and seemingly overburdened by expectation, Tottenham reverted to fallible type. For the second time in a week Brighton damaged a north London club’s top-four challenge, with Leandro Trossard’s late goal, stolen after Cristian Romero’s slip in his own box, repeating what happened to Arsenal at the Emirates. Romero, stumbling in tackling Adam Lallana, the late substitute, presented Trossard with the chance to score the winner Brighton - and Tottenham - deserved. Until a volley from Steven Bergwijn following Trossard’s goal Robert Sánchez in the Brighton goal barely had a shot to face, and none on target, his work usually done for him by a defence throwing in repeated heroic blocks. For that top-four race Arsenal’s visit to Tottenham on 12 May now looms large, though Brentford, Leicester and Liverpool must first be negotiated by Antonio Conte’s team. To end two seasons of absence from the Champions League they must find far greater intensity than in losing to Brighton at home for the first time since 1981. Graham Potter, linked with the Spurs post vacated by Nuno Espírito Santo in early November, has often suffered for Brighton’s inability to score while pointing to the quality of his team’s performances. Two goals at Arsenal represented two-thirds of Brighton’s output in their last eight Premier League matches and a less goal-shy team might have taken these three points earlier. Not that Potter minded. “I thought the performance was a step up, actually,” he said, in comparison with the Emirates win. “We asked some questions. It wasn’t a smash-and-grab game. We knew we had to be good and I thought we were today.” Brighton pressed aggressively, closing space before the ball could reach Harry Kane in his trademark deep-lying positions.Conte barking from the edge of his technical area. He stayed there throughout, though the Italian, like his team, seemed lower amped than normal. From the start, they had “Brighton was very good at closing the space,” Conte said. “We moved the ball slowly. We will have to do much better than today. Perhaps the more fair result was a draw but Brighton is a good team. If you win at Arsenal and Tottenham away it means that it’s a good team.” Losing the recently outstanding Matt Doherty for the rest of the season had brought Sergio Reguilón into the left wing-back position ahead of Ryan Sessegnon. Without the Irishman, a team that had scored 17 in five previous matches stalled, though Brighton deserve credit for cutting off further supply lines. Kane and Son Heung-min’s partnership barely featured, the South Korean anonymous until he had a pair of shots blocked at the start of the second half, first by Joël Veltman and then by Trossard’s scamper back to join the all-hands effort. The remaining member of a previously all-conquering attacking trident, Dejan Kulusevski, was booked in the first half for flinging an elbow at Marc Cucurella. And that was as prominent as the Swede got before being withdrawn in favour of a similarly ineffectual Lucas Moura. As Brighton hustled and hassled and made sure to take their time over breaks in play, Spurs’ frustrations were shared by home fans beginning to sniff an archetypal slip-up. “We executed the gameplan perfectly,” said the Brighton captain, Lewis Dunk. “We could hear the crowd getting frustrated.” Yves Bissouma, patrolling, striding in front of Brighton’s defence, was outstanding. “Tactically, he was really good,” said Potter. “You can see his quality. His high end is of Champions League level.” After taking an early knock when Cucurella whipped the ball away when he was shaping to shoot, Kane swiftly recovered his step, if not his influence. Spurs went into the break with a wobble very much in the offing. Much of their energy had gone into trying to get Enock Mwepu a second yellow card. Potter took the hint in removing the Zambian at half-time in favour of Danny Welbeck, who soon hit a hopeless shank wide. With Harry Winks introduced into midfield, Spurs attempted to step it up for the last 15 minutes. Pierre-Emile Højberg’s scamper to the byline and cutback went unrewarded as Reguilón desperately slid beyond the ball. And meanwhile Brighton continued to compile more chances, before at last the ball fell to Trossard. The Belgian’s decisive cut inside and finish would be the coolest piece of play seen all afternoon.