Trocon Davis picked off a pass at the Princeton goal line and returned it 100 yards to break a tie 61 seconds before halftime and the Tigers went on to a 29-7 Ivy League victory Saturday.
Yale had begun a drive at the 39-yard line of Princeton (5-4, 3-2) after an interception of its own and reached the 5. Davis, a junior, intercepted running back Mordecai Cargill's pass for his first career pick and returned it the length of the field for a 14-7 lead.
The return matched James Anderson's 100-yard interception return against Cornell in 1984 as the longest in Princeton history.
The Tigers tacked on a touchdown and a 2-point conversion on the opening possession of the third quarter, driving 65 yards in nine plays with Connor Michelsen completing four passes and Quinn Epperly running for the final yard.
Cargill carried 24 times for 101 yards for Yale.