It was Moorestown's third straight T of C title and 77th straight win overall.
That capped the third consecutive perfect season for Moorestown (26-0), meaning that McCool and the team's other seven seniors did not lose a game after their freshman year.
It was easy to understand why after Saturday.
With her team losing by two goals to start the second half, McCool, lightning-quick and exceedingly fluid, took over the game.
The senior midfielder, bound for North Carolina, scored four straight goals in a span lasting a little less than five minutes.
Her free-position goal with 20 minutes, 19 seconds left made the score 5-4. Her final score, with 15:53 left, gave Moorestown a 7-5 lead, and the Quakers mostly controlled the ball from there.
"They were putting pressure on me, but honestly, I like when I get pressured," McCool said. "I like using my speed around that. And that's what I got to do each time - getting in, faking and shooting.
"It's so special [to win this game]," she added. "At halftime, I didn't even think about losing. . . . I'm so proud of us for keeping our composure and doing awesome. I'm really going to miss every single girl on this team."
Moorestown took a 3-2 lead on a goal by Alex O'Donnell with 14:57 left in the first half.
But Summit quickly took control, dominating possession, scoring three consecutive goals, and going into halftime with a 5-3 lead.
"The first half was a little shaky, but the second half was amazing," said Quakers junior Adriana Pendino, who netted two goals. "Our coach really talked to us and got us going. And Marie's run just got us all pumped up."
McCool completely stifled whatever momentum Summit built in the first half. Moorestown's 5-0 run was capped by Pendino's score with 13 minutes left, putting the Quakers ahead by three goals.
Summit's only goal after intermission, with 12:09 left, came on one of its few meaningful possessions of the half.
"I'm so proud of every member of this team," Knobloch said. "Marie definitely turned it around in the second half and gave us that spark that we needed.
"It's just an overwhelming feeling of pride for me, for this coaching staff, and for this team that fought so hard to get to this point."
Summit 5 1 – 6
Moorestown 3 5 – 8
Goals: S-Sara Szynal 3, Olivia Kelly 2, Catherine Cordrey; M-Marie McCool 4, Adriana Pendino 2, Alex O'Donnell, Kayla Pruitt.
Saves: S-Kady Glynn 7; M-Gabby Cooper 1, Jessica Goralski 4.