Fleetwood, who extended their winless run to four League Two games, had been hoping to reignite a play-off charge at Adams Park but it was Stewart who had the last laugh.
Ainsworth admitted it was so tight at the bottom of the division that now his side had moved to 48 points for the season it is onwards and upwards for Wycombe, with relegation now out of the question.
"We're just happy to get back-to-back wins," said Ainsworth. "I'm really pleased and I think personally 48 or 49 points could get you relegated still this season but that's taken the pressure off.
"It's very close down there so it'll be nice just to get one more win and get in the 50's and then I'll probably concede that we're safe.
"Fleetwood are a strong side, very physical and they have aspirations of promotion this season so it's a good scalp for us and probably a marker for how far we've come.
"Anthony Stewart has come up with a great winner and I'm so pleased for him. At the end of the game I think we had six or seven teenagers on the pitch and it's great for Wycombe. I'm really proud of the way those youngsters are coming on.
"We're looking up as well and it's probably time to look up the table and see what we can do."