The Dark Blues looked down and out when they trailed 19-6 early in the second period, but three tries in 16 minutes from full-back Sam Egerton, flanker James Harries and substitute Charlie Marr left Cambridge crestfallen.
Marr added one conversion and a 78th-minute penalty to seal the deal, while centre Cassian Bramham-Lawl booted two first-half penalties after Oxford lost their captain John Carter through injury.
Wing Andy Murdoch scored Cambridge's solitary try just before the interval, with full-back Rob Stephen kicking four penalties and a conversion.
- Sports & Recreation
- James Harries