But it was another tough afternoon for Birmingham as once again they were reduced to ten men with the controversial sending off of Damien Johnson in the first half.
Replays of the tackle on Kevin Kilbane - who was not injured - suggested that a yellow card might have been sufficient, but in the current climate it was no surprise to see the red card brandished.
Birmingham had defender Martin Taylor back for his first Premier League appearance since his sending off against Arsenal for his tackle on Eduardo which ended the Croatian star's season.
Taylor replaced the suspended Frank Queudrue in the only change from last week's win over Manchester City.
Wigan had former Blues midfielder Wilson Palacios back from suspension but were still missing banned midfielders Michael Brown and Jason Koumas.
The Latics had the first chance after Birmingham failed to clear a free-kick fired into the box by Ryan Taylor.
Ex-Blue Mario Melchiot worked the space well before squaring the ball to Marcus Bent but the on-loan Charlton striker blasted it well over the bar.
Wigan threatened again when Bent picked out strike partner Emile Heskey with a telling ball, but the England man had strayed just offside.
The Latics snatched the lead after 15 minutes when Antonio Valencia's speed took him clear of Martin Taylor and the cross was perfect as Ryan Taylor raced in unchallenged to fire a low left-foot shot into the corner of the net.
Wigan went close to grabbing a second as the dangerous Valencia had a vicious strike scrambled away.
Keeper Maik Taylor was forced into action dealing with a shot from Heskey as the home side kept up the pressure.
Birmingham briefly turned the tide but it took 25 minutes before Chris Kirkland was in action saving a speculative long-range effort from Gary McSheffrey.
But Birmingham suffered a massive blow with the 37th minute sending off of Johnson for a two-footed lunge at Kilbane. Referee Mike Dean - who sent Martin Taylor off in the Arsenal game - had no hesitation in reaching for the red card.
And the Blues had a real let-off when Paul Scharner - making a club record 73rd Premier League appearance - let fly with a tremendous shot.
Maik Taylor was powerless and relieved to see it hit the foot of his right post and he was fortunate again when Bent fired wide from eight yards.
But ten-man Birmingham almost levelled it just before half-time when Argentine striker Mauro Zarate curled a shot just wide.
Wigan had an early chance after the break when Heskey hammered a shot wide but the killer goal came on 55 minutes. A deflected Valencia cross was flicked on by Bent and turned back inside by Scharner with Ryan Taylor poking it home.