The teams have played each other in the last 12 league finals and are expected to do the same this season. La Salle (6-5, 6-0 league) has won nine of the last 10 league titles. Prep (9-3, 6-0) last won in 2011.
Before the stoppage, Prep senior Pat Walsh scored his second goal to even the score. The midfielder absorbed a check just inside midfield, dodged three La Salle defenders, and raced toward the net.
Each side scored just once in the first half before rallying for four goals in the third quarter.
Christopher Hladczuk scored the game's first goal halfway through the first quarter. The La Salle freshman attack finished a pass from Zachary Drake.
Prep's Steve Bradley tied the game with 5 minutes, 26 seconds left in the first half. The Hawks entered halftime with a lead thanks to a goal from Peter Gayhardt.
Walsh's first goal gave the Prep a 4-3 lead with four minutes left in the third. Lightning struck in the distance, but not close enough to suspend play.
La Salle answered with two goals, including Aidan Kerrigan's go-ahead score. The Explorers led by one with just 90 seconds left in the quarter.
Surely, they would take a lead into the fourth. But then Walsh found the net and lighting struck close enough to warrant a suspension. La Salle's lead was relinquished. The Explorers would have to wait a day to try to regain it.