A BRACE from James McClean and a bullet header from Leon Barnett gave Latics their eighth win on the bounce and moved them up to fifth in the Championship table.
Despite falling behind to Tommy Smith’s 19th-minute goal, the visitors had too much for Mick McCarthy’s men to pick up another three points.
McClean grabbed the equaliser within two minutes of Latics falling behind, with a cool finish after good work from Emmerson Boyce and Marc-Antoine Fortune.
Latics went into the break in front when Jordi Gomez’s free-kick was nodded home by Barnett, with Town goalkeeper Dean Gerkin left in a pickle.
The visitors squandered a great chance to go further in front at the start of the second half when they failed to make the most of a three-on-one breakaway from an Ipswich corner.
But it mattered not, and goal number three duly arrived when Fortune’s cross from the right was slotted home at the far post by McClean.
The remainder of the game was a formality as Town possessed neither the creativity nor the drive to get back into the game.
McClean was denied the chance for a hat-trick to mark St Patrick’s Day when he was replaced by Stephen Crainey, possibly with one eye on Tuesday’s visit of Yeovil.
But the jubilatioon in the away end that greeted the final whistle underlined what a massive victory this was for the club.
Latics: Al Habsi; Boyce, Ramis, Barnett, Perch; McArthur, Tunnicliffe, Gomez; McClean, Waghorn, Fortune.
Subs: Carson, Crainey (for McClean, 82), Kiernan (for Barnett, 74), McEachran, McManaman, Powell (for Waghorn, 64), Maynard.
Ipswich: Gerken; Chambers, Berra, Smith, Cresswell; Anderson, Hyam, Williams, Skuse, Hunt; Murphy.
Subs: Loach, Mings, Green (for Skuse, 63), Tab, Richardson, Taylor (for Anderson, 71), Ebanks-Blake (for Williams, 78).
FOR A FULL REPORT, REACTION AND PICTURES, SEE MONDAY’S WIGAN EVENING POST