In the bottom of the seventh inning, Long, a 6-foot, 190-pound senior righthander, set off the celebration with a pair of three-pitch strikeouts.
"We knew these guys could hit," said Long, who is ticketed for Lehigh. "To shut them down like that, it's a really good feeling."
Long fired a three-hitter with eight strikeouts. C.R. South's only run, in the fourth inning, came because of a three-base error.
"He did a great job of changing speeds on his fastball," Golden Hawks coach Greg Young said.
After yielding two first-inning singles, Long, who went 11-2 this season with 74 strikeouts in 77 innings, was all but unhittable.
"Kev's been coming in and shutting down people all year," La Salle senior third baseman Mike Piscopo said. "Even when he would get behind in the count today, he would battle back and get the batter. That's huge."
Rebounding from a 5-4 loss to Neumann-Goretti in the Catholic League semifinals, the Explorers (23-3) won five straight en route to the crown.
"It's just incredible that we came this far after such a tough loss," Baiada said. "I think a lot of that had to do with the confidence we have in each other."
In the second, Piscopo's single past first base advanced Tyler Kozeniewski (leadoff walk) to third. Colin Pyne, who was 2 for 2 with a sacrifice bunt, plated Kozeniewski with a single to center field.
La Salle made it 3-0 in the fourth. Piscopo's single to right-center knocked in pinch-runner Jim Herron (Baiada had led off with a double to right-center). Dom Cuoci's two-out liner to left, with C.R. South's infielders playing in, brought home Kozeniewski.
"We really weren't anxious before the game," said Piscopo, bound for Northeastern. "We practiced hard and were confident coming in. We prepare so well. Come game time, we're ready."
For the 23-3 Golden Hawks, senior lefthander Bret DeStefano went 51/3 innings. He allowed six hits and four walks before giving way to Brian Donnelly.
In the second, after giving up a two-out double to Mike Chaykin and plunking Steve Wright, Long got Zach Fitzgerald to fly out to right.
"They were the better team today," said Young, who is stepping down after 10 seasons. "They took advantage of our mistakes."
La Salle 0102000 - 362
Council Rock South 0001000 - 131
WP: Kevin Long. LP: Bret DeStefano. 2B: LS-Corey Baiada; CRS-Mike Chaykin.
Contact Rick O'Brien at firstname.lastname@example.org, or @ozoneinq on Twitter. Read his blog, "The O'Zone," at www.philly.com/ozone