Penn has taken a major step toward becoming the regular-season Ivy League basketball champion and earning the top seed in the four-team tournament.
The Quakers avenged their only Ivy League loss with Saturday's 74-71 win over Harvard at the Palestra.
Penn (21-7, 11-1 Ivy League) is now one game up on Harvard with two left — at Yale (7-5) and Brown (4-8) this coming weekend.
Harvard (15-12, 10-2), closes out with home games against Cornell (5-7) and Columbia (5-7).
Penn, at this point, isn't focusing about an expected rematch with Harvard in the Ivy League tournament.
"I am thinking about the next weekend, [that's] all I am focused on," said senior point guard Darnell Foreman, who had a strong floor game with 14 points, five assists and just one turnover in 31 minutes.
The Quakers have now won four in a row since a 76-67 loss at Harvard and nine of 10.
It was senior night for Penn and the atmosphere was fitting of a first-place showdown, with 6,586 cheering virtually the entire game.
"I thought it was a great college basketball game," Penn coach Steve Donahue said. "There are very few places like this on a Saturday night in February and I am grateful that I am part of it."
In a game that was tight all the way, Penn extended its lead to 70-65 on a three-pointer by Caleb Wood with 29 seconds left on a feed from Foreman.
"He gave me a great pass and was the reason I was so wide open," said Wood, who scored 10 points.
Harvard kept coming and cut the lead to 73-71 on a three-pointer by Corey Johnson with 3.1 seconds left.
Penn's Ryan Betley, made one of two free throws with 2.5 seconds remaining and Seth Towns' desperation half-court shot at the buzzer was way off, securing the win for the Quakers.
Forward AJ Brodeur had 17 points and 12 rebounds and hit all six of his field goal attempts in the second half. Betley added 16 points.
Towns, a 6-foot-7 sophomore, had a game-high 22 points for Harvard.
In Harvard's earlier win over Penn, the Crimson kicked it down low to 6-foot-9 sophomore Chris Lewis, who scored a career-high 25 points. On Saturday, Lewis was limited to nine points on 4-for-9 shooting as the Quakers swarmed on him frequently when he got a low-post touch.
"I thought they collapsed on him and made it very difficult for him to have space to work," Harvard coach Tommy Amaker said.
Amaker was gracious in defeat.
"Penn is a tremendous basketball team with weapons and shooters and are very hard to defense," Amaker said. "I thought they were very deserving of the victory tonight."