After the Leopards shot holes through Penn's defense to build a seven-point halftime lead on 65.2 percent accuracy, Penn coach Jerome Allen let the Quakers know he wanted more of a commitment.
"If you defend, you're always going to have an opportunity to win," Allen said. "We did a poor job in the first half of guarding them. In the second half, for about 15 minutes, we did a much better job."
The difference was dramatic. The Quakers limited Lafayette to 9-for-28 shooting in the second half. During one stretch, the Leopards went 7 minutes, 49 seconds without a field goal, which allowed Penn to rev up its offense in transition and turn a 44-40 deficit into a 58-48 lead.
"For the first 15 minutes of the second half, we brought a lot of energy," Rosen said. "Our energy and effort were there. Like coach said in the locker room, the question is: Where was that in the first half? But that's for us to get better at and hopefully we can build off that 15 minutes."
A pair of free throws by Rosen gave the Quakers a lead (47-45) they would not relinquish and kick-started a 14-1 run. Rosen did what true point guards are supposed to do - he penetrated the lane and either found an open teammate cutting to the basket or kicked the ball out to the perimeter for an open jumper. Or he would score. He played 38 minutes and had only two turnovers.
A key for the Quakers was holding down Lafayette sharpshooter Jim Mower, a 6-foot-3 junior from St. Joseph's Prep who ranked third in the nation in three-point shooting (46.5 percent). Both Rob Belcore, a 6-6 junior, and promising freshman guard Miles Cartwright put the clamps on Mower, holding him to six points on 2-for-7 shooting. Last season, Mower torched the Quakers for 21 points.
"We wanted to make him work for every opportunity he got," Allen said.
Along with Rosen, Jack Eggleston (12 points), Tyler Bernardini (12) and Andreas Schreiber (10) reached double figures for Penn.
In recent days, it was like old home week for Lafayette coach Fran O'Hanlon. The Philly native was an assistant coach at Penn under Fran Dunphy from 1989 to '95, which covers the years Allen starred for the Quakers. On Saturday night, O'Hanlon was honored by Villanova, his alma mater. He was presented with a framed jersey with his No. 22.
Contact staff writer Ray Parrillo at 215-854-2743 or rparrillo@phillynews.com.