The Frenchman, who famously turned down a move to the Stadium of Light, struck three minutes into injury time and was promptly sent off for removing his shirt in celebration having already been booked.

Kaboul’s strike sparked wild celebrations on the sidelines and among the small band of travelling supporters behind Marton Fulop’s goal.

Their mood was in stark contrast to that of Black Cats boss Steve Bruce and the home fans among a crowd of 37,578, as Pompey became just the third side this season to leave Wearside with anything to show for their efforts.

Sunderland had taken the lead through Darren Bent’s 10th goal of the season with 23 minutes gone, but although Andy Reid hit the bar with an 80th-minute free-kick, they failed to push home their advantage and were made to pay at the death.

They have now won only one of their last seven league games, and that has taken the gloss off a positive start to the campaign which had the more optimistic of followers dreaming of European qualification.

Bruce had described the game as arguably his side’s biggest of the season after yet further fruitless away trips to Wigan and Fulham, and with injuries and suspensions severely limiting his options, there was an edginess around the Stadium of Light ahead of kick-off.

However, Bruce and the home fans need not have worried as Pompey, having secured their first victory under Avram Grant last weekend, showed few signs of putting any pressure on a drastically re-shaped defence.

With three of last Sunday’s back four sidelined Phil Bardsley and Kieran Richardson through suspension and Anton Ferdinand with an ankle injury Nyron Nosworthy, Paula da Silva and the fit-again George McCartney were drafted in, and they could hardly have asked for a more comfortable re-introduction.

Fulop had only one shot of note with which to deal, and Jamie O’Hara’s fifth-minute effort never looked like over-taxing him.

Instead, the returning James in the Portsmouth goal found himself in regular action, and but for his 18th-minute save from Jones, the Black Cats might have taken the lead earlier than they did.

However, the home fans had to wait only five minutes longer for the opening goal.

Teenage midfielder Jordan Henderson found space down the right and after pushing the ball through defender Marc Wilson’s legs crossed to the far post.

Reid did well to feed the ball back across goal, where the unmarked Bent turned smartly to lash a left-foot shot past the helpless James.

Henderson curled a 28th-minute effort inches wide with James rooted to the spot, and Wilson survived appeals for a penalty for handball as he challenged for a cross as the clock ran down.

The only black spots of the first half for the home side were the bookings collected by skipper Lorik Cana and McCartney, with the combative Albanian in particular living dangerously thereafter.

Sunderland picked up where they had left off after the break with Bent forcing an important block from Richard Hughes after running on to Nosworthy’s pass within two minutes of the restart.

But Pompey responded and after an extended period of pressure, Fulop found himself having to keep out O’Hara’s curling 53rd-minute free-kick.

Kanu wasted a promising counter-attack four minutes later when he fired harmlessly wide after combining with O’Hara and Aruna Dindane, and as the game opened up, there were opportunities at both ends.

Nosworthy, who was finding plenty of space down the right, might have done better when he blasted over from a tight angle with 58 minutes gone, and Jones scuffed a shot on the turn just wide on the hour.

Wilson denied Bent with an important 70th-minute block and James kept out Cana’s header from the resulting corner as Sunderland turned the screw.

They were unfortunate not to increase their lead with 10 minutes remaining when, after Kaboul, Tal Ben Haim and Bent had all been booked after a bout of handbags, Reid curled a free-kick against the crossbar with James nowhere.

The small band of travelling supporters behind Fulop’s goal were on their feet with a minute remaining when Kaboul cut inside from the right and unleashed a fierce shot, but the keeper was in the right place at the right time.

Cana blocked Kaboul’s goal-bound effort deep into injury-time, but the Wearsiders failed to deal with the corner and the same man stabbed home a precious equaliser.

Kaboul’s celebrations were cut short by the red card, but even that could not spoil his afternoon.