The Holton Arms team jumps back into the pool to celebrate its Washington Metropolitan Prep School Swim Dive League championship Friday in Laurel. (Eric Goldwein/The Washington Post)

Gonzaga’s title fate was sealed well before William Mudlaff closed out the 400-yard freestyle relay, but the celebration was only getting started. First, the team sang “Na na na na na na na na, hey hey hey, goodbye.” Next came the trophy collection, followed by more chants and another celebratory jump in the pool.

It’s all part of a long-standing tradition, Mudlaff said. And so is winning.

On Saturday at Fairland Aquatic Center in Laurel, the Eagles captured their seventh consecutive Washington Metropolitan Prep School Swim Dive League (WMPSSDL) championship.

“The boys always get behind the lane and get really rowdy for the relays. That’s definitely one of the most special parts of Gonzaga,” Mudlaff said. “Hearing them cheer behind the lane, that definitely gets the energy up and helps up swim fast.”

Gonzaga (430 points) finished well ahead of Georgetown Prep (308) and Good Counsel (277), rebounding from a disqualification for a false start in the 200 freestyle relay prelim and consistently placing in the top three thanks to heavy doses of both depth and talent.

“It’s been incredible to be a part of this team. Especially winning four years in a row,” Mudlaff said. “I know that’s something that not too many teams have accomplished a lot in the past, and it’s special being part of that.”

Holton-Arms (321) won the girls’ title, holding off Good Counsel (267.5) and last year’s champion, Holy Cross (259). The Panthers relied on contributions from across their deep lineup, led by Jing-E Tan, Sydney Mathis, Olivia Jubin and Jillian Johnson.

“This is my fourth year coming to WMPSSDLs, and it’s so great winning as a senior,” Mathis said.

The Panthers gained ground in the relay events, capping the night with a second-place finish in the 400 relay as Mathis nearly completed an impressive comeback on the final leg.

While Mathis collected the trophy, the rest of the Panthers lined up on the side of the pool and jumped in.

“It’s a really good feeling, and everyone’s putting in their best effort,” Tan said. “It’s really rewarding.”

Matthew Braviak set the tone for Gonzaga by winning his first varsity race in the 200 freestyle (1:43.6), a result that surprised his teammates and himself.

Junior Ryan Windus placed first in the 50 freestyle (20.53) and the 100 freestyle (45.56) and helped Gonzaga win the 200 medley relay (1:34.02) and place third in the finale of the 400 relay (3:10.59) in front of his noisy Eagles teammates.

“That’s part of the Gonzaga tradition,” Windus said. “Everybody comes out on deck whether you swim or not, and [they] get rowdy.”

Mudlaff said the championship celebrations don’t get old. “Not for a second,” he said.

The senior is hoping the team can enjoy one more at the Metropolitan Interscholastic Swimming and Diving Championships.

“We’re definitely going in firing on all cylinders. We’re ready to go,” Mudlaff said. “We had some really strong swims from some underclassmen, we had a lot of people drop a lot of time, so I think that we’re set up well to perform well next week.”