The championship game is next Sunday, May 27.
Facing a Maryland program yesterday that has collected more national championships than any other women's lacrosse team in history, Penn immediately went into a sizable hole, trailing 4-0.
But Penn received two goals each from Allison Ambrozy, Melissa Lehman and Becca Edwards - whose score with 18:19 left to play gave the Quakers the lead for good at 6-5.
The loss was only Maryland's second to Penn in 15 all-time meetings. The 16-4 Terrapins, Atlantic Coast Conference members whose most recent title came in 2001, have a record nine championships.
"We haven't played an ACC team, and clearly they have a great conference," said Penn coach Karin Bower, who guided Penn to its first Ivy League crown in 25 years.
"We respect Maryland, and were excited to play them and show what we could do against them."
In extending its school record for wins in a season to 13, Penn had to overcome the 4-0 deficit and trailed 5-3 at halftime.
But Penn, which hadn't made the NCAAs since 1983, was not about to let the rare opportunity to win a national championship at home get away.
"They [Maryland] go really hard and really fast, and probably faster than a lot of teams we've played," Bower said. "I think we were back on our heels, and our attack was a little bit nervous at the beginning.
"But we settled down. We've had two big games where we came from behind - Dartmouth and Syracuse - and so our team knew if we could settle down, and keep playing good defense, our shots would start falling."
Penn tied it at 5-5 on a goal by Chrissy Muller with 21:39 remaining, and about three minutes later, Edwards scored an unassisted goal as Penn went ahead for the first time.
About a minute earlier, Edwards had just missed on an attempt from in close that clanged off the left pipe.
"I hadn't been shooting well, and I knew it was time to focus because we were doing well," Edwards said.
The Quakers led, 8-5 at the 14:17 mark, and 9-6 at 9:43. The Terrapins scored their last goal with 4:04 to go.
Men's quarterfinals. John Glynn scored with 4.8 seconds left in overtime to send undefeated Cornell to the men's Division I lacrosse Final Four with a 12-11 victory over Albany yesterday at Princeton Stadium.
Cornell (15-0) meets the winner of today's Duke (15-2) vs. North Carolina (10-5) game in the NCAA semifinals on Saturday at M&T Bank Stadium in Baltimore.
Senior goalie Matt McMonagle, an Episcopal Academy grad, made 12 saves against Albany (15-3).
Senior Henry Bartlett, from Penn Charter, scored Cornell's first goal of the game.
In the other quarterfinal at Princeton, junior Kevin Huntley scored five goals as third-seeded Johns Hopkins (11-4) rolled to a 14-6 win over Georgetown (12-3). The Blue Jays play the winner of today's University of Maryland-Baltimore County vs. Delaware noon match.
Delaware, the CAA champion, is 12-5. UMBC is 11-5.
Contact staff writer Kevin Tatum at (215) 854-2583 or email@example.com.