Premier League - Henderson brace downs Wigan
Henderson gave the hosts the lead when he lashed home from inside the box, before Stephane Sessegnon picked himself up after an Antolin Alcaraz foul to score from the spot.
Sessegnon then turned supplier to pick out the unmarked Henderson to slot home on 76 minutes and, although substitute Franco Di Santo notched a late consolation for Wigan, they were well beaten by their rampant opponents.
Steve Bruce welcomed the club he managed twice back to The Stadium of Light knowing that his Sunderland side had failed to beat the Latics since he took over at the helm of the Wearsiders.
Despite Bruce's midweek comments that he was looking at a top 10 finish, Roberto Martinez’s Latics sat just five points behind Sunderland prior to kick off with the Latics having won their latest battle in the war of attrition that typifies this season’s relegation scramble, beating Blackpool 3-1 last week.
In contrast, after a bright start to the year, the Black Cats have been in freefall, failing to win in their last nine matches, and they found themselves on the fringes of the fight for survival.
With the stage set for another desperate encounter, Sessegnon found Danny Welbeck after two minutes but the off-balance striker could only stab his shot well wide.
Wigan keeper Ali Al-Habsi was forced to punch Henderson's cross from under the bar midway through the half and, as the hosts pressed, Ahmed Elmohamady delivered a teasing near post cross for Gyan, but the Ghana international was unable to direct the ball on target.
It was Wigan who came closest to breaking the deadlock on the half hour mark.
Former Latics man Lee Cattermole had hardly put a foot wrong but when he was dispossessed in a dangerous area, Hugo Rodallega warmed Simon Mignolet's hands with a rasping shot from just outside the box.
But it was the hosts who finished the half on the ascendancy.
Gyan stumbled after he drove into the box when poised to pull the trigger and it needed a thumping Gary Caldwell tackle seconds later as he looked to twist into the area to alleviate the danger.
Elmohamady almost had the final word of the half with a cross that zipped across the Wigan goal but Jack Colback was unable to react in time and the chance went begging.
Sunderland looked to carry on where they left off after the break as a dipping Gyan header had Al-Habsi scrambling to tip the ball over his bar, but it was the visitors who took the lead out of nothing.
Charles N'Zogbia played in Diame, and when the Senegal man cut inside he let fly with an unstoppable shot past the desperate Mignolet.
If Wigan felt they could build on the lead, they were found out within three minutes. Sub Steed Malbranque played a superb cross into the edge of the six-yard box and Gyan powered a header home.
Al-Habsi almost gifted Onuoha another chance after flapping at a corner, but the Wigan backline were caught out to greater effect almost immediately.
Sulley Muntari dinked a pass into the box and, after Henderson chested the ball down, he swivelled and blasted past Al-Habsi.
N'Zogbia then fired a free-kick straight at the Sunderland keeper as the Latics tried to find a way back, but it was game over on 73 minutes.
Alcaraz bundled Sessegnon over in the box and the midfielder picked himself up to roll the penalty into the bottom corner to give the Black Cats a two-goal cushion.
And it went from bad to worse for the visitors three minutes later. With the Wigan defence all at sea, Sessegnon had time and space to pick out the unmarked Henderson who stroked the ball past Al-Habsi for his second.
Wigan threatened sporadically through Moses, but Muntari could have found a fifth Sunderland goal only to shoot well wide of Al-Habsi's goal.
There was still time for Ben Watson to force Mignolet into a routine save from a free-kick, but when Di Santo slid the ball home from a matter of yards, Wigan were already down and out.
The Wearsiders' victory gives them breathing space and propels them to 10th in the table, but for Martinez, the reverse sees Wigan slide back into the bottom three. The Latics have four games left to preserve their season - including what may prove to be a mouth-watering winner-take-all encounter with West Ham on May 15.