Ange Postecoglou’s side looked completely in control at the Amex and ready to move into the top six when they built a 2-0 lead through goals from Brennan Johnson and James Maddison in a completely dominant first half on the south coast.
But Brighton, who had looked down and out, turned the game around after the break with Danny Welbeck heading the winner after Yankuba Minteh and Georginio Rutter had also found the net – leaving Postecoglou shaking his head in disbelief.
It was a terrific response from Albion, who hadn’t won in the Premier League since August, and another big moment for Welbeck, 33, who is enjoying a renaissance this season, with his fourth goal of the campaign.
It was breathless stuff, but once Brighton were ahead in the 66th minute, Tottenham simply didn’t have the mental or physical energy to respond. They now drop to ninth, with Brighton in the top six in their place.
That’s remarkable because Spurs had dominated the opening 45 minutes, not only scoring goals from Johnson and Maddison but also running the show in imperious and energetic fashion.
So, Postecoglou could be excused for looking completely bemused as his players lost the plot in the second half, just as reporters were preparing headlines that the north London club look like being serious top-four challengers this season.
That’s how good the first half performance was, but Brighton bettered it with their attacking energy after their break.
Spurs should have gone ahead early on, especially when Maddison was clean through but saw his shot blocked and then when Timo Werner had a headed effort ruled out for offside.
But the goal came eventually when Maddison won the ball back in midfield and Dominic Solanke put Brennan Johnson through for his sixth goal in the last six games in all competitions after 23 minutes.
Remarkable when you consider at the start of the season, Spurs fans were split on whether the former Nottingham Forest winger deserved his place in the side.
He certainly isn’t polarising opinions anymore. Only one Tottenham player has ever scored in seven games in a row – legendary striker Clive Allen back in 1987 when he finished with 49 goals - and despite this result Johnson still has an opportunity to join the club when Tottenham face West Ham after the international break All in all it was a frustrating start for Brighton, who lost defender Adam Webster to injury after only nine minutes and never really got a grip on the game early on.
It was 2-0 after 37 minutes when Maddison, left unmarked on the edge of the area, stroked home a shot that goalkeeper Bart Verbruggen will feel disappointed to let through his grasp. It was, however, no more than Spurs deserved as the Amex was stunned into silence.
Albion, however, changed the narrative after that. Having looked dead and buried they started the second half quickly and found a wayinto the match when the outstanding Kaoru Mitoma swung over a low cross which Destiny Udogie inexplicably missed, leaving Minteh to sweep home.
Then, with Mitoma running the show, they snatched an equaliser when Rutter ran on to Mitoma’s pass and finished efficiently with his left foot.
Welbeck’s header, after the Spurs defence gifted Rutter a chance to reach a ball he had no right to get to, completed the turnaround by the 66th minute, with young Albion manager Fabian Hurzeler taking the plaudits for inspiring his team’s remarkable response.
Spurs, by contrast, looked completely shot, unable to muster any kind of fightback as Brighton cruised through the final 20 minutes in impressive style.
Postecoglou, just when he thought he had cracked it, has a lot of thinking to do.
BRIGHTON: Verbruggen 5; Veltman 5, Webster 5 (Igor 9), Dunk 6, Kadioglu 5 (Estupinan 46; 6); Baleba 6 (Wieffer, 74; 6), Hinshelwood 6; Minteh 7, Mitoma 8, Rutter 7 (Enciso, 73; 6); Welbeck 7.
TOTTENHAM: Vicario 6; Udogie 5, Van de Ven 6, Romero 6, Porro 7; Kulusevski 7, Bentancur 6 (Bissouma 79; 6), Maddison 8 (Moore 85; 6); Johnson 8, Solanke 7, Werner 6 (Sarr 79; 6)
Referee: David Coote