PRINCETON, N.J. (AP) Henry Caruso scored 13 points, Pete Miller had nine points and 10 rebounds and Princeton held off Penn's second-half rally to beat the rival Quakers 72-71 on Tuesday night to finish the regular season 13-0 at home.
Princeton was up by 18 with 14:52 remaining and seemed on its way to easily stay perfect at home for the first time since the 2010-11 season.
But Penn outscored Princeton 35-19 over the final 10:15.
On Penn's last possession that started with 3.2 seconds left, Jackson Donahue curled around the 3-point arc to get the inbound pass and drove the lane, but his pass inside to Darien Nelson-Henry was intercepted and time ran out.
Devin Cannady and Spencer Weisz each added 11 points for Princeton (22-6, 12-2 Ivy League), which has won eight of the last 10 in the series.
Princeton jumped out to a 36-25 lead at the break after making 13 of 27 shots, including 4 of 8 from 3-point range.
Matt Howard led Penn (11-17, 5-9) with 15 points.