Jermain Defoe returned to haunt Tottenham Hotspur manager Juande Ramos as the Portsmouth striker set up a 2-0 victory that kept his former club rooted to the bottom of the Premier League.
Defoe was allowed to leave White Hart Lane last season after failing to impress Ramos but the England star got his revenge at Fratton Park.
He opened the scoring with a first half penalty after Jermaine Jenas had carelessly handled and played a key role in Peter Crouch's second half header.
Portsmouth had Lassana Diarra sent off in the closing moment but Spurs couldn't avoid a fourth defeat in six league matches.
Ramos's side have made their worst start for 53 years and increasingly resemble a team in total disarray.
The pre-season departures of Dimitar Berbatov and Robbie Keane have left them bereft of any attacking threat and Ramos appears uncertain how to get the best out of his new signings.
While it is too early to talk of a relegation fight, Spurs' lofty ambition to break into the Champions League places has already been reduced to a pipe-dream.
Portsmouth had conceded 10 goals in their last two games so boss Harry Redknapp was relieved to welcome back former Tottenham centre-half Sol Campbell and French midfielder Diarra.
Ramos dropped leading scorer Darren Bent and also left Luka Modric on the bench as he handed recalls to David Bentley, Gilberto and Michael Dawson.
Defoe was playing against his former club for the first time and the Portsmouth forward had the ball in Tottenham's net in the third minute, but his clinical strike was correctly ruled out for offside.
Portsmouth threatened again soon after when Richard Hughes, stretching to hit Defoe's lay-off, forced a fine save from Heurelho Gomes.
Hughes drew another impressive stop from Gomes with a low volley from the edge of the penalty area that the Tottenham keeper smartly parried away.
Spurs were clearly lacking confidence and cohesion. Jamie O'Hara's tame shot straight at David James midway through the half summed up their uncertainty.
Ramos's side were set-up in damage-limitation mode with five in midfield but that just invited pressure and they cracked in the 33rd minute.
Glen Little whipped in a free-kick from the right and Jenas rashly stuck out his arm to control the ball.
Referee Mike Dean immediately pointed to the spot and Defoe stepped up to lash the penalty past Gomes. He made a point of keeping his celebration to a minimum as a mark of respect to his former supporters packed behind Gomes's goal.
Ramos replaced Gilberto with Aaron Lennon at half-time and Didier Zokora with Giovani dos Santos just before the hour mark.
Tottenham briefly sparked into life when Bentley shot just wide before Dean waved away appeals for a penalty when Diarra appeared to handle Lennon's cross.
But Portsmouth went further ahead in the 68th minute with a superbly-crafted goal.
Defoe turned Dawson on the edge of the area and picked out Armand Traore wide on the left.
The on-loan Arsenal youngster drove in a low shot that Gomes could only parried towards Crouch, who rose to head into the empty net from close-range.
The sense of crisis enveloping Spurs deepened when Ramos's decision to send on Bent in place of Roman Pavlyuchenko was greeted by chants of ‘you don't know what you're doing’ by Tottenham's unhappy fans.
Diarra was sent off in the 88th minute for a second booking after making a rash lunge on Benoit Assou-Ekotto but Spurs were already down and out.
