Malvern Prep's Matt Mackrides won't have much time this summer for normal teenage activities like hanging at the Jersey Shore with friends or lounging at the neighborhood pool.

That's because Mackrides is part of the U.S. under-19 squad that will compete in the International Lacrosse Federation World Championships in Coquitlam, British Columbia, from July 3 to 12. Much of next month will be devoted to practicing for the event.

"I'm looking forward to it," said Mackrides, a senior attackman and midfielder for the Friars. "It's a great honor."

Last night, in the opener of an Eastern Pennsylvania Scholastic Lacrosse Association semifinal doubleheader at Garnet Valley, Mackrides produced a hat trick and junior Conor Steidle tallied four times as Malvern Prep ousted Inter-Academic League rival Penn Charter, 14-7.

In the thrilling nightcap, Conrad Ridgway scored with one-tenth of a second remaining in the second overtime to give La Salle a 7-6 victory over Haverford School.

On Tuesday night, back at Garnet Valley, the second-seeded Explorers (29-2) and top-seeded Malvern Prep (21-2) will meet for the EPSLA championship. The winner of that game will play for the Keystone Cup on June 6, either in Western or Central Pennsylvania.

La Salle needed the last-second heroics of Pete Schwartz to escape the third-seeded Fords (17-7). The junior forced the overtime when he found the net on a 20-yard, left-side shot with eight-tenths of a second left in regulation.

For the Friars, the 5-foot-9, 170-pound Mackrides scored all of his goals in the final 11 minutes. The 2006 state champions defeated the 12th-seeded Quakers (16-13) for the third time this season.

"They're a tough team, a big team," Mackrides said.

Malvern Prep had a 4-2 lead at intermission and, on Steidle's third goal, stretched it to 10-4 with just over seven minutes to play.

Mackrides' older brother, Andrew, starred in lacrosse for the Friars and recently finished his career at Penn State. Following in his brother's footsteps, Mackrides will play for the Nittany Lions.

Mackrides, an 18-year-old who lives in Newtown Square, earned one of 23 spots on the U.S. national team last July in a tryout of about 120 players at Maryland-Baltimore County. Locals Matt Dolente (Malvern Prep, Johns Hopkins) and James Green (Central Bucks East, Ohio State) also made the cut.

For Penn Charter, which yielded four straight goals at the start of the third quarter, Yale-bound Colin Still and Ohio State recruit Eddie Bambino each scored a pair of goals.

Penn Charter 1 1 2 3 - 7

Malvern Prep 2 2 4 6 - 14

Goals: PC–Colin Still 2, Eddie Bambino 2, Joey Sankey, Ryan Goldman, Stephen McVeigh.

MP–Conor Steidle 4, Matt Mackrides 3, Matt Conte 2, Ryan Creighton 2, Colin McGeehin, Bobby Hill, Chris Layne.

Saves: PC–Dan Carr 10. MP–Andrew O'Connell 7.

Haverford School 2 2 0 2 0 - 6

La Salle 1 1 2 2 1 - 7

Goals: HS–Rory O'Connor 4, Ben Bourke, Joe O'Rourke. LS–Pete Schwartz 3, Matt Lynch 2, Randy Forster, Conrad Ridgway.

Saves: HS–Dan Wigrizer 7. LS–Niko Amato 10.

Contact staff writer Rick O'Brien at 610-313-8019 or robrien@phillynews.com.