Bought by the Sunderland manager, Martin O'Neill, from Bursaspor for £3m, Alfred N'Diaye could be one of those January signings who gives panic buying a good name. The French midfielder's full debut for the Black Cats was outstanding. Barrel-chested, slightly knock-kneed, the 22-year-old covered an extraordinary amount of ground, breaking up any number of Wigan attacks with tackles and interceptions, distributing the ball intelligently and creating one of two goals for Steven Fletcher.

Even at the end, when Sunderland were desperately hanging on, N'Diaye was diving to head the ball clear from his penalty area.

"We've had to show a lot of fight and determination, and we did that," said O'Neill. "N'Diaye is a strong lad, his vitality is there to see, and when he learns about the game – because he's still very raw, he's only 22 – he'll be really good. He's only been around the club for a short time, and when he gets to know the players he'll do great for us."

Having fallen behind early, when David Vaughan deflected Ronnie Stam's low ball into the six-yard box past his own goalkeeper, Sunderland responded in some style. They may have been slightly fortunate to be awarded a penalty when Sebastian Larsson's free-kick hit the arm of James McCarthy, albeit that said arm was raised at the time, but after Craig Gardner had sent Ali al-Habsi the wrong way from the spot they sensed Wigan's vulnerability and in Fletcher, had the man to exploit it.

His first goal owed all to N'Diaye's wonderful cross from the left. Habsi pulled off a brilliant save from Fletcher's initial header, but the ball looped up and the goalkeeper was still on the floor when Fletcher volleyed it stylishly into the empty net.

His second, and 10th of the season, was a superb finish after Adam Johnson had controlled and laid off Fletcher's flick-on off Gardner's long free-kick. From the edge of the box Fletcher had plenty to do, but his first-time side-footed shot into the top corner was as beautifully timed as it was unerringly accurate.

The second half saw a spirited Wigan fightback orchestrated by Shaun Maloney who, having already hit the outside of the post with a free-kick, crossed for Manchester United loanee Angelo Henríquez to head home and set up a frantic final 10 minutes or so during which the Latics were unlucky not to create an equaliser.

"It's one of those days that you finish the game and feel you have nobody to blame except yourself," said the Wigan manager, Roberto Martínez, who brought his new signing, the Honduras international Roger Espinoza, on at half-time to make his home debut.

"If we had done things better for a period of 25 minutes in the first half we would have won the game. The fact we coped with the adversity of giving Sunderland a two-goal lead and came out and controlled the second half is a cause for satisfaction, but the penalty affected us too much – we couldn't keep the ball, and didn't play well at all, but still shouldn't have conceded two goals."

Wigan have now slipped back into the relegation zone – Sunderland's win, their fifth in eight games, lifting them into 11th – but Martínez remains confident his side will preserve their Premier League status for a ninth consecutive season. The key may be to find a replacement for centre-back Ivan Ramis, out for the season after injuring a cruciate ligament at Fulham. "We weren't good enough for 30 minutes, but we can rectify that," Martínez said. "Ramis's injury last week cost us today's points."