The Wanderers started well, scoring through Noah Cato with just nine minutes on the clock. Cambridge replied through full back Toby Berridge four minutes later, but when Tom Stephenson crossed three minutes after that the Wanderers didn't look back.
Cato starred in a line-up boasting seven players with past or present Cambridge connections, emphasising the close link between the two clubs, and was instrumental in the visitors' attacks.
Cambridge had had the best of the opening 10 minutes before Cato coasted through the home defence from the 10-metre line. Captain Greig Tonks converted from in front of the posts, and eventually finished with eight successful kicks.
Berridge immediately replied for the hosts, benefitting from a slick passing move instigated by Elliot Bale and dummying Cesar Sempere for a fine try, which Bale converted.
Saints turned up the heat, with Tom Stephenson scoring the first of his three, before Anders Mogensen and Cato again dotted down.
Two more from Stephenson, one from Tonks, and one each from Jordan Husband and Tom Collins in the second period before Cato's coup de grace give the impression that Cambridge crumbled.