Owen Coyle backed young goalkeeper Lee Nicholls to come back stronger from the glaring error that contributed to Wigan's costly Europa League defeat by Zulte Waregem.
The Latics went into the game knowing victory over the Belgians, who they drew with in their first ever European game in September, would send them through to the last 32.
All looked rosy when Leon Barnett gave them a seventh-minute lead, and they missed a number of chances to add to it.
But in the 37th minute Wigan lost the ball from their own corner and it ended up with Zulte's Thorgan Hazard on the right side of the penalty area.
The Belgian, the brother of Eden and on loan from Chelsea, hit a well-struck shot that Nicholls tried to catch only for the ball to squirm through his hands and into the net.
The real sucker punch then came two minutes from time when Junior Malanda curled a fine effort into the top corner to earn Zulte a 2-1 win.
Francky Dury's side are now in pole position to join Rubin Kazan in the knockout stages, with Wigan needing to beat Maribor in Slovenia in their final Group D game and hope table-toppers Rubin can defeat Zulte.
Nicholls, 21, came into the team a month ago after Scott Carson suffered an ankle injury and had made a very positive impression.
Coyle said: "He's been terrific since he came in. I've told him that as much as he's made a mistake he'll play on Sunday again because that's the confidence and the belief that we have in him.
"We'll pick him up and he'll go on to have a great career, I've got no doubts about it.
"If a goalkeeper makes a mistake then invariably it results in a goal. I had a career as a striker and I missed chances every game, but when you play at the top end of the pitch and you get a goal then all is forgotten.
"He's been terrific up to now and that's the life of a goalkeeper. He'll be stronger for the experience as hurtful as it is, and I know how conscientious he is.
"He's got a big career ahead of him and that's what he's got to focus on."
The main frustration for Coyle and Wigan was that they allowed Zulte to get a foothold in a game in which they had been totally outplayed.
Hazard's shot was the first time Nicholls was called upon while his opposite number Sammy Bossut made saves from Callum McManaman, James McClean and Nick Powell in the first half before denying Powell again in the second.
Coyle said: "I thought it was a very good performance from the lads, we controlled the game.
"We were 1-0 up and it should have been two or three, and that's come back to bite us because we had the chances to put the game to bed.
"The young kid's made a mistake, which can happen to anybody. In the second half we still had chances, probably not as many as the first half, but certainly over the 90 minutes there's no doubt we probably deserved to win that game.
"I think they had two shots on target all night. The boy's obviously had a wonderful finish late on, although we think we could have avoided the build-up in terms of the easy possession in the box.
"It's a cruel game and that's what's happened tonight. We're hurt, of course we are, because we wanted to qualify, it would have been fantastic for the football club."