Princeton (16-9, 9-2 Ivy) is one-half game ahead of the Crimson (17-9, 9-3 Ivy), who lost 75-72 to Pennsylvania. The Tigers are on the road for their final three Ivy contests, while Harvard will play its last two at home.
If the teams finish tied, they would meet in a playoff for the second time in three seasons to earn a National Collegiate Athletic Association tournament berth.
Tyler Melville scored 23 points for the Big Green and Gabas Maldunas added 17 at L. Stockwell Jadwin Gymnasium in Princeton, New Jersey.
Will Barrett led Princeton with 24 points, including five 3-pointers in the second half, and T.J. Bray contributed 21.
At Palestra in Philadelphia, Tony Hicks scored 24 points and Darien Nelson-Henry added 18 for the Quakers (8-20, 5-6 Ivy).
Wesley Saunders led Harvard with 20 points followed by Christian Webster with 16.
In other conference games last night, Brown beat Columbia 61-58 and Yale defeated Cornell 79-70.
To contact the reporter on this story: Nancy Kercheval in Washington at email@example.com
To contact the editor responsible for this story: Michael Sillup at firstname.lastname@example.org