Charlie Wyke set up 10-man Wigan's winner on his first appearance since suffering a cardiac arrest last year as the Latics beat Birmingham 1-0.
The striker's last competitive fixture came in November before he suffered a cardiac arrest in training.
But he made an quick impact at St Andrew's as he set up fellow substitute Nathan Broadhead's 82nd-minute strike that earned Wigan their first win of the season.
Wigan had been playing with 10 men since Joe Bennett was sent off in the 10th minute but they held kept Birmingham out before clinching victory late on.
Leam Richardson's men had drawn all three of their league games so far this season and they again highlighted that they are hard to beat.
John Eustace's hosts made a promising start, with Przemyslaw Placheta firing over before Lukas Jutkiewicz - brought into the starting line-up in place of Troy Deeney - was involved in the first big talking point.
Juninho Bacuna threaded a first-time through ball into the former Burnley striker's path and, as Jutkiewicz prepared to race clear on goal, he was adjudged to have been clipped by Bennett, who was shown a straight red card.
Bacuna curled the resulting free-kick narrowly wide.
The Blues looked to make their advantage tell and Scott Hogan saw an effort blocked by Jack Whatmough before the visitors went agonisingly close themselves as Tom Naylor fired just wide from inside the penalty area.
In a lively spell, Auston Trusty's inviting ball reached Hogan at the far post but, sliding in at full stretch, he could only divert his effort over the crossbar while Jordan James bent a shot wide of Jamie Jones' left post.
As the half went on, Blues struggled to create chances and Wigan grew in confidence, with Will Keane seeing an effort blocked just before the break.
The hard-working visitors looked comfortable in the early stages of the second half while Blues tried to up the tempo, Bacuna seeing an effort deflect wide and Jutkiewicz's looping header easily gathered by Jones.
The hosts threw on Deeney and Jonathan Leko in an effort to make the breakthrough after 58 minutes, with Jutkiewicz and Josh Williams making way.
Wigan remained in the hunt for three points themselves though as Max Power's low drive from the right forced John Ruddy into a save.
The hosts had their best chance of the half after 81 minutes as substitute Sam Cosgrove's well-struck shot was turned away by Jones.
And the frustration mounted further for Blues a minute later as Wyke - on as a 70th-minute substitute - did well down the left before playing in Broadhead to fire low past Ruddy.
Jobe Bellingham saw a late effort saved and Dion Sanderson fired over as Blues desperately looked to claw back a point but Wigan held on for an impressive win.
What the managers said...
Birmingham's John Eustace: "It was frustrating. I thought we started the game very well in the first 20 minutes. We were excellent. The sending off obviously changed the way the game went. It was frustrating not to be able to break them down.
"Most importantly it was really disappointing to lose the game. (There are) lessons to be learned and we will certainly be doing that."
Wigan's Leam Richardson: "You know my thoughts on Charlie the person, never mind the footballer, and I know how hard he has worked from nine months ago to get back in training and get back on the pitch.
"There was never going to be anybody who could stop him. All I had to do was support him and give him that platform to do that. I thought his touch was fantastic so he has obviously been doing something while he's been away! His assist was great as well."