Defoe was essentially signing off for the week, with the former Tottenham man cup-tied for the FA Cup semi-final against West Brom next weekend.

These are lively times at Fratton Park. And Pompey’s fans went home singing and dancing but spare a thought for Wigan, who fielded a patchwork team and suffered a harsh defeat in their bid to beat relegation.

Pompey missed chances early on – even Defoe, skying an eight-yard chance after Latics goalkeeper Chris Kirkland kept out Hermann Hreidarsson’s blast and Niko Kranjcar was just wide with a free-kick.

Yet it was Wigan, without an entire midfield in the suspended Michael Brown, Jason Koumas and Wilson Palacios and minus knee injury victim Erik Edman, who should have gone ahead in the 13th minute.

Marcus Bent, recalled to replace £3million striker Marlon King, looked offside when he slipped Antonio Valencia through to slide a shot past James. Glen Johnson looked certain to score an own goal but his desperate clearance thudded against the crossbar and away.

It fell straight to Valencia but this time the South American’s shot was deflected for a corner.

Bent almost surprised James with a shot from distance that flew over the bar but there had been little sign of ingenuity on either side by the half-hour mark.

But Pompey finally snatched the lead in the 33rd minute and, inevitably, it was Defoe who poached it.

John Utaka, the £7million Nigerian winger who has been accused of being too laid-back by boss Harry Redknapp, showed admirable determination, cutting in from the right to almost stumble through three challenges and then see his cross deflect off Emmerson Boyce and leave Kirkland and the covering Mario Melchiot stranded.

Defoe nipped in on the far post to tuck home the chance – his seventh goal in seven games.

Pompey certainly had the breaks but they almost had a second goal as well soon afterwards when Kranjcar let go from well outside the area and Kirkland had to fly across his goal to touch the ball away with his fingertips.

It was enough to set off the Pompey faithful on a rousing selection of their Wembley repertoire of songs although Paul Scharner’s long shot for Wigan almost quietened them as it flew past a post.

And there was a blow for Wigan just before the break when Emile Heskey was led off after being pole-axed by a collision with Sol Campbell’s stray elbow.

The big former England striker came out good as new for the second half but was largely starved of service as Pompey began to take command.

The ever-willing Milan Baros, yet to score his first Pompey goal, should have buried Wigan after a delightful run, typical of his industry in the 51st minute. He tried to pick out Defoe’s run but the ball came back to him off a Wigan leg and he failed to deliver the shot from a clear opportunity when a combination of Kirkland and Boyce put on the block.

James kept himself warm by diving to save Scharner’s long-range drive just before Hermann Hreidarsson, doubtful all week with a swollen knee, limped off to give the home side a Wembley scare.

But even that was forgotten when referee Alan Wiley pointed to the spot soon afterwards. Valencia went down in the area after running onto Bent’s pass and Sylvain Distin appeared to make clear contact despite Pompey’s protests.

But James, atoning for his so-called howler in Paris, flung himself in the way of Ryan Taylor’s poorly-struck penalty and the midfielder, instead of potting the rebound, scooped it over the bar, holding his head in horror.

His number was kindly held up soon afterwards as manager Steve Bruce made a sympathetic substitution.

But Wigan with just one defeat in their previous five games, pressed to the finish in search of another precious survival point and James had to make another outstanding stop five minutes from time, flying to keep out substitute Antoine Sibierski’s cracking drive before Defoe broke clear again to settle it in stoppage time.