Ian King almost gave United a dream start, after just 45 seconds his free kick beat keeper Wilkerson but came back off the bar. Jason Soloman, Richard Harvey, King again, Gary Crawshaw and Corey Browne all went close as the Rebels were happy to hear the half-time whistle.
The second period was more even as Slough relied on the breakaway. Browne wasted a great chance after 55 minutes, volleying over from close range.
Slough broke the deadlock on 77 minutes when a Fiori cross deflected to ex Duck Eddie Denton and he buried a low shot past Richard Wilmot.
Two minutes from time a flying Cliff Hercules header went just wide as Slough were let off the hook.
Aylesbury United Line up
Richard Wilmot, Jason Court, Cliff Hercules, Warren Kelly, Kenrick Roudette, Richard Harvey, Ian King, Jason Soloman, Ian Rutherford, Gary Crawshaw, Corey Browne. Subs: Mark Rooney, Steve Butler, Jermaine Darlington