Nakhi Wells popped up with the winner with 10 minutes to go, after Jussi Jaaskelainen had failed to hold on to Elias Kachunga's long-range effort.
It was virtually the only effort on goal from either side, neither of whom appeared to lack the quality to win a game that was there for the taking from the off.
"Of course I am very pleased with the three points and the result," said Wagner.
"And I was also pleased by the attitude showed by my players.
"Maybe the performance wasn't quite there in the first half, but we brought the right attitude, which is important to be successful.
"We had a fighting attitude, and we were also patient which is very important against a team like Wigan, who have a threat on the counter.
"We had the right balance behind the ball, to avoid the counters, but technically we weren't quite there.
"In the second half, when we had a little bit more space, we created some moments - and Nakhi put one of them into the net.
"This is why we deserved the result at the end."
Wagner hailed his side's matchwinner, whose future has been the subject of a great deal of speculation of late.
"Of course it's important he stays at this club, just like any other player in this squad," the Town boss added.
"He did exactly what he is paid to do, as a striker, just like my goalkeeper did exactly what he is paid to do, keep a clean sheet.
"Nakhi is a positive character, who is a natural goalscorer.
"He has had long periods when he didn't score, and now he is having a period - I think four goals in six games - where he is taking his chances.
"This is important for us, and he is one of the reasons why we are having a successful period."