He levelled it up with a terrific finish after Dimitar Berbatov had shot Spurs into an early lead - the first time the Wigan defence had conceded in six consecutive home games.
Wigan made just one change from Monday's momentous draw at Chelsea with Australian midfielder Josip Skoko dropping to the bench and Michael Brown returning to the starting line-up against his old club.
Keeper Paul Robinson and England defender Jonathan Woodgate were among the Tottenham absentees and former Latics favourite Pascal Chimbonda failed a late fitness test on his damaged calf.
Spurs threatened inside the first minute with skipper Robbie Keane beating Emmerson Boyce for speed, but the shot failed to test Chris Kirkland.
Aaron Lennon then set up the sixth minute opener. His cross from the right took a slight deflection off a Wigan defender and Berbatov was unmarked at the back post to stab it home.
Keane blazed over with another attempt before Wigan had a sniff with Marcus Bent forcing a save from Radek Cerny.
But the equaliser came on 12 minutes when Kevin Kilbane picked out Chelsea goal hero Heskey, who turned superbly to rifle past the keeper as Didier Zokora and Jamie O'Hara tried desperately to get in the block.
The Latics threatened again when Bent's determination took him past both Alan Hutton and Jermaine Jenas before forcing the save from Cerny.
Wigan survived a penalty appeal when Berbatov went down in the box with Mario Melchiot appearing to pull him over as he went for a corner.
Spurs piled on the pressure as half-time approached and Ryan Taylor cleared off the line to deny Michael Dawson as the Latics struggled to clear the ball after a series of corners.
After the interval, the Latics should have had the lead when Wilson Palacios slid a superb ball to the unmarked Bent but, with only the keeper to beat, he smashed his shot against the crossbar.
The Latics also went agonisingly close when Cerny just managed to smother the shot from Luis Antonio Valencia inside his six-yard area, and he managed to hang on to it as Heskey tried to force it home.
Antoine Sibierski replaced Heskey but blew the chance of instant glory by blasting hopelessly off target with his first touch.