Cambridge remain winless in League One after going down 2-1 at Wycombe.
The Chairboys began the stronger and took the lead within eight minutes.
Aaron Morley’s long ball beat the United offside trap, allowing the former Jamaican international to run through on Vincente Reyes’ goal.
He could have squared it to Dan Udoh who was poised for the pass, but McCleary took the shot on and with the help of the right-hand post, Wanderers went a goal up.
It was his second of the season and his first at Adams Park since January.
Wanderers looked strong but were handed a real sucker punch midway through the half, as Dan Nlundulu equalised for the visitors on 22 minutes, with a smart finish from close range.
However, the second period was one-way traffic, as the Chairboys dominated.
Bez Lubala, Josh Scowen, Richard Kone and Kieran Sadlier all went close.
But with five minutes left, Cameron Humphreys slammed home Wycombe’s winner with a well-taken left-footed finish.
Cambridge remain bottom whilst the Chairboys move into ninth.