David Sullivan’s belief in morality will be severely tested after this humiliation. When West Ham United’s co-owner appeared on television before kick-off, he pinpointed a desire to do “what’s right” as the reason for backing Slaven Bilic when speculation over the manager’s future mounted last month. By full-time, however, those noble sentiments had a hollow feel. Chairmen tend not to worry about shows of loyalty when they see their side display the tactical cohesion of a pub team.

While the anger raining down from the stands was a form of torture for Bilic – whose job must be hanging by a thread after this defeat – it was music to Brighton & Hove Albion’s ears. They have waited a long time to experience the feeling of winning away in the top flight – 34 years to be precise – and how they cherished putting that statistic to bed at the London Stadium, executing Chris Hughton’s immaculate plan to perfection.

On 1 March 1983 Brighton won 2-1 at Swansea City in the old First Division. The scoreline was far more emphatic here and the harsh reality for Bilic is that Brighton, up to 10th after this victory, could have helped themselves to more than three goals. In the end they settled for Glenn Murray opening his account for the season and José Izquierdo scoring for the first time since a £16m move from Club Brugge.

“I’ve been around enough to know this is the type of division where you can lose three, four or five games on the spin,” Hughton said. Brighton’s manager was talking about whether his team had altered perceptions of themselves but it was a line that felt pertinent in the context of West Ham’s display. After starting the season with three straight defeats West Ham had responded to adversity by picking up eight points from five matches. Bilic was entitled to think that they were turning the corner. He saw encouraging signs in training during the week. “We thought this was going to be the game to lift us up the table,” he said.

That, unfortunately, was not the prelude to Bilic lavishing praise on his players. Instead he was ashen-faced and downbeat as he analysed the shambles he had just witnessed. He accepted the blame. “I don’t want to hide or run away,” he said. “It is my responsibility. Of course I can’t be happy with our performance. With the greatest respect it is one of those games where you are expecting to win.”

He quickly clarified that remark. “It is not expecting the win will come if you only show up on the pitch,” Bilic said. “I didn’t see that we didn’t try.” But he did see flaws. He pointed to too much ordinary play in the final third, criticising his forwards for being too passive, while there were gaping holes in West Ham’s defence.

The onus was on the hosts to seize the initiative. Instead Brighton took control, pressing high and passing with pleasing crispness and intent, threatening on the right thanks to Bruno’s overlapping runs beyond Anthony Knockaert. Their boldness paid off when Murray, capitalising on lazy marking from Pedro Obiang, glanced Pascal Gross’s free-kick past Joe Hart in the 10th minute.

West Ham toiled as they sought to overcome Brighton’s diligence and organisation but they would end the evening without forcing Maty Ryan to make a noteworthy save. Manuel Lanzini struggled to shake off Dale Stephens and Davy Propper, Michail Antonio’s end product was wayward and Javier Hernández was isolated against the excellent Lewis Dunk and Shane Duffy.

The growing frustration took on an extra dimension when Brighton, satisfied that West Ham had little to offer without the suspended Andy Carroll’s battering ram qualities, attacked shortly before half-time. Moments after Hart made a fine save to deny Murray at the end of a flowing counterattack, Izquierdo gathered possession on the left, stepped past Obiang and aimed for the far corner from 20 yards. Hart got a hand to the Colombian winger’s bending effort, but managed only to push it into the corner of the net.

Bilic responded by tweaking his system at half-time, replacing Cheikhou Kouyaté with Andre Ayew, but there was a whiff of desperation about throwing on another forward so early. The change had no effect. West Ham were still a confused mess, bereft of wit or spark, and Brighton remained comfortable and dangerous.

The home side’s difficulties were summed up when Marko Arnautovic, their £24m summer signing, was jeered off in the 74th minute. Not that the departure of their record buy led to an improvement. A minute after Arnautovic’s withdrawal, Pablo Zabaleta’s trip on Murray allowed the Brighton striker to complete West Ham’s misery by sending Hart the wrong way from 12 yards. “The board will do what they are going to do,” Bilic said. “It’s their decision.”