Leven chipped Vale keeper Stuart Tomlinson from all of 45 yards to put United 2-1 ahead, although it needed a late penalty save from goalkeeper Ryan Clarke to secure victory over a spirited Vale side.
Wilder said: “It was a fantastic goal to win it, but I would have been very disappointed if we hadn’t won.
“Pete’s a good player and ever since he walked through the door he’s been a great lad, great to work with.
“We’ve given him a platform to show his skills off.
“Clarkey (Ryan Clarke) will get a bit of credit and so will Pete (Leven), but it was a fantastic performance from us.”
Wilder was disappointed by the decision to award a penalty against Duberry.
He said: “To give a soft penalty like that was not how he refereed the game. That’s what we said to him and the keeper’s made a fantastic save and managed to secure the three points.”