Cortlan Davis-Havill put Cambridge on the scoreboard in the first half but Melville went into the interval 2-1 ahead.
However, the strong finish by the Cambridge visitors saw the lead change.
First, Dylan Lake levelled at the start of the half.
Ten minutes later, Davis-Havill scored his second and then Hamish Durran-Wolff found the net on the hour.
The youth league takes a break next weekend (Queen’s Birthday Weekend).
Photographs: Joanne Kelk