Cheltenham went ahead in the 56th minute when Jamie Cureton finished Jason Taylor's cross.
And although the home side levelled through substitute Matt McClure, Billy Knott turned a Sam Deering cross into his own net to condemn Wycombe to a fifth game without a win on the back of a last-gasp loss at Swindon on Tuesday.
"It was a hangover from Tuesday, it was a lacklustre performance and not one we've come to expect at Wycombe," Ainsworth said.
"I didn't think we deserved to win the game at all. If we'd have drawn the game we would have been lucky even though their winner was a wicked deflection.
"But we have to get over it as quickly as possible.
"We felt it was unjust at Swindon and we probably carried that with us. But I will address it.
"We have played well in some home games, we were just lacklustre. They were there for the taking, they weren't impressive at all, but we gave them the points,
"I don't like that and it won't happen very often in the future - we need to make sure those nothing games go in our favour.
"It was hard that second goal. It did take them to score their first for us to kick in. We did create a few chances after that but there is no way we would have deserved it.
"We just about got what we deserved but at least we don't get hammered anymore."
- Sports & Recreation
- Jamie Cureton
- Sam Deering
- Billy Knott