The visitors missed a penalty in the 32nd minute when Phil Heath blasted his spot kick high over the bar after Darren Collins had been brought down in the area by Kelly.
The Middlesex hosts opened their account in the 65th minute when Brown's low left wing cross was turned into his own net by Ducks defender Kevin Day at the near post.
It was eventually two in the 85th minute when Kelly's high ball over the United back line found Pearce who sidestepped keeper Simon Gregory before tapping into the empty net.
Just a minute later an attempted back pass by Day fell woefully short and Baker gleefully blasted home.
Then, in the 88th minute, Wingfield was upended by Ducks defender Paul Benning in the area but from the resulting penalty Wingfield sent his spot kick sailing over the bar.
It was 4-0 in stoppage time when Wingfield's shot was blocked and Pearce followed up to smash home from close range and complete a miserable afternoon for the visitors.
David Figg