After Freddy Eastwood had cancelled out Dean Morgan's opener for the hosts Steven Craig popped up to head home what proved to be a winner just after half an hour as the home side held on after the break.
This was Wycombe's first taste of victory since opening day but manager Ainsworth believes there will be plenty more wins around the corner if his troops defend like they did against Southend.
"I knew the onslaught was coming," he said. "Southend are a strong side and they'll be there or thereabouts come the end I guarantee it.
"If we can play that every week we'll be up there and in the top half of the league which is my aim.
"We showed here as well as at Oxford that not only can we go forward but how well we can defend.
"I thought Gary Doherty and Leon Johnson at the back were a brilliant pairing. I told them I want them out there leading and they put their bodies on the line.
"I think the turning point was the end of the first half when they hit the bar and had three or four shots and we just put our bodies on the line. That's how I want the boys to be. I'm really pleased with our defensive display.
"I think the clean sheets will come. We've got a fantastic goalkeeper in Matt Ingram and he'll pull off saves that others won't.
"We've carried on from last week (when they drew 2-2 with Oxford) after feeling hard done by. I said if they carried on with that performance they'll get the result and I felt they thoroughly deserved it."
- Sports & Recreation
- Freddy Eastwood
- Steven Craig