The forgotten striker - last capped three years ago and discarded too soon according to his manager - was outstanding as Wigan made it two wins in four days to storm up the Premier League table.
He scored the first goal, played his part in the second, a Denny Landzaat penalty, and earned the spot-kick for number three, scored by Antoine Sibierski.
Wigan were unchanged with £2million ex-Fulham midfielder Michael Brown on the bench after suspension.
Roy Keane predictably made changes with Dwight Yorke, Kieran Richardson,and Anthony Stokes back after missing the midweek draw at Birmingham.
Keeper Chris Kirkland faced early danger when he was forced to keep out a Richardson near-post effort after Wigan gave away an early corner.
And he also did well tipping a Michael Chopra free-kick over the bar after Paul Scharner's foul on Yorke ten yards outside the box.
But otherwise, Wigan were in charge. They had a penalty appeal turned down when Heskey went down under the challenge from Nyron Nosworthy but ref Mike Riley appeared to get it right.
Wigan took the lead after 19 minutes when Antonio Valencia's ball into the box took a deflection to Heskey, who came up with a confident finish although the Latics striker did appear to be offside.
Heskey was unlucky to be pulled back for offside as he raced clear and Wigan fans were fuming again when a strong penalty claim from Jason Koumas failed to impress Mr Riley.
Kirkland kept Wigan's lead intact with a save from Daryl Murphy after Richardson set up the chance but Craig Gordon was just as effective at the other end turning a Heskey header over the bar from Landzaat's free-kick.
The lively Heskey did have the ball in the net again but this time he was nabbed for offside and Wigan had to settle for a 1-0l half-time advantage.
Sunderland went close when Andreas Granqvist blocked from Ross Wallace but the Latics got the all-important second goal after 61 minutes.
Sibierski was bundled over by sub Danny Collins chasing Heskey's header and this time the ref had no doubt, and Landzaat made no mistake from the spot.
Heskey was then brought down by Russell Anderson and Sibierski hit his third of the season from the spot.