Allyson Heavens made her game-winning goal sound simple.

"I just wanted it, and I just took the goal," said Heavens, whose second score of the game, with 22 seconds left, gave Garnet Valley a 12-11 victory over Harriton in the PIAA state girls' lacrosse quarterfinals Saturday at West Chester East.

It was the third time the teams met this year. Ten days ago, Harriton evened the season series with an 11-10 win. Garnet Valley coach Kate Henwood credited her team's ability to adapt as a factor Saturday.

"We made a couple adjustments," Henwood said. "When a team plays each other three times, and it's a one-goal game each time, it could really go either way. The focus was really on us playing our game and not letting them take us out of that."

Early on, the Rams tried to do just that.

Harriton controlled the game and led, 6-4, at halftime thanks in part to senior Jessica Schwab's three goals. After a Caleigh Foust score for Harriton with 3 minutes, 36 seconds left before halftime, Henwood called a timeout to regroup her defense.

"The defense started off really strong, but then had a bit of a lapse, Henwood said. "After that timeout, the defense really responded and never looked back.

"They are the reason we won this game. They played excellent today."

The Jaguars (22-3) scored one minute into the second half on a shot by Haley Warden. The excitement faded quickly, though, as Schwab netted her fourth of the game just 34 seconds later. The Rams (20-5) were leading by 8-7 when Rutgers-bound senior Halley Barnes attacked the Harriton defense.

In consecutive possessions midway through the second half, Barnes was stopped at close range on great saves by Harriton goalie Melina Avery.

The sequence left Barnes frustrated, so she turned to her coach to help shake it off.

"That was a big mental game for me," Barnes said. "My coach pulled me aside after those two, and she got me out of my own head."

Barnes then scored three consecutive goals in the next three minutes and assisted on a Heavens score to put the Jaguars ahead, 11-8, with 6:42 remaining.

The Rams did not go away, though, as Schwab added two more goals, including her 400th career point, to bring the score within one. With 58 seconds left, Harriton evened the game with Foust's third goal.

With the game seemingly destined for overtime, Heavens made a cut toward the goal.

"I realized that I beat my girl and it was a wide-open lane," Heavens explained, "so I looked at the left corner and shot there."

The goal put the Jaguars in the state semifinals on Tuesday against Central League rival Radnor at a site and time to be determined.

Garnet Valley   48-12

Harriton   65-11

Goals: GV-Halley Barnes 5, Sabrina Fusco, Allyson Heavens 2, AnnaElise Morello, Ashley Pyle 2, Haley Warden; H-Caleigh Foust 3, Jane Henderson 2, Jessica Schwab 6.

Saves: GV-Kate Stroup 8; H-Melina Avery 9.

Contact Tom Mahon at rallysports@phillynews.com.