Wigan boss Paul Cook rued his side's inability to make their chances count after seeing Swansea claim a 2-1 smash-and-grab victory with a stoppage-time winner.
After Kieffer Moore's 21st-minute penalty had cancelled out Nathan Dyer's 12th-minute opener, Wigan dominated against their promotion-chasing opponents.
But Jamal Lowe hitting the crossbar was the closest the home side came to scoring the goal their performance warranted.
And they saw a point snatched out of their hands two minutes into added time when Swansea substitutes Connor Roberts and Sam Surridge combined for the latter to win it with a fine header.
"Swansea are a good side, with good players, and they caused us problems in the first half with the way they moved the ball," said Wigan boss Cook.
"We got to grips with that in the second half, we negated a good side to one which didn't offer a threat – our goalie's not touched the ball second half.
"We've created chances again, that's the crux of it, and it's the biggest thing in football.
"When those moments come in games, you must take them.
"Unfortunately for us, we're finding ourselves on the receiving end of some very heavy punches at the moment.
"The chances come, we don't take them, but that's football."
Wigan's defeat was their eighth in the Championship this season and leaves them with 15 points from as many games.
"As a manager, you must keep believing in the players, you must keep working away, which we will do," Cook added.
"Our fitness is good, everything about us is good.
"Unfortunately, that points tally is not what we've deserved, but we know how football works."
Swansea boss Steve Cooper was delighted with the three points, which he felt his team were made to work hard for.
"Having gone 1-0 up early, I think there was an opportunity for us to keep going and play well and dominate the game," Cooper said.
"And we are a little bit disappointed we weren't able to capitalise on the good start we made, and gave away a poor goal.
"I know they had a lot of corners and balls into our box, but our goalie's not really had to make a save in the game.
"The reality is we defended them really well, and when you do that you always give yourself a chance to win the game.
"We left it until late, but it was a great cross, a great header and we're all very happy."
Despite languishing at the wrong end of the table, Wigan's loss was only their second at home this season, following Leeds' victory here in August.
"Wigan have a great record here, and amassed a huge number of points here last season as well," Cooper added.
"We knew that coming in to the game, and we told the players it would be tough given their home record.
"We knew all that would mean a tough game and, even though we planned to have more control, we knew there'd be moments we'd have to handle.
"And we were able to do that, maybe a little more than we would have liked, but we did it really well."
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