At a time when sport specialization has become the norm, Matt Carney has spent the past four years at Potomac School juggling three sports. Depending on the season, the senior took the field for the Panthers as a football defensive end, basketball power forward or lacrosse midfielder.

“You need a little time [between sports] to get your energy back together,” said Carney, the only player on all three teams. “It’s something I’ve gotten used to, and I absolutely love to do it every year.”

Carney’s commitment paid off in full on Sunday when the Potomac School boys’ lacrosse team beat Flint Hill, 12-3, in the Mid-Atlantic Conference final, finishing off a banner athletic year for the McLean private school. With Carney’s help, the Panthers won MAC titles in three of the most high-profile boys’ sports — football, basketball and lacrosse — in the same school year for the first time.

“We feed off the excitement,” said sophomore Kevin Havermann, who is also a quarterback on the football team. “We go into each season with the same goals, and to get my second MAC championship, I’m honestly at a loss for words right now.”

Potomac School (14-4) closed out the run in convincing fashion against Flint Hill (10-11), controlling nearly every aspect of the game. It was the second straight outright MAC crown for the Panthers, who have not lost a conference game since falling to the Huskies in the 2010 final.

Carney, senior Alex Prezioso and Havermann scored three goals apiece to pace the offense, while junior goalie Parker Hornstein made 14 saves and held the Huskies to just one goal in the final three quarters. Junior Jack O’Brien and sophomore Connor Sweeney combined to win 15 of 19 faceoffs, helping the Panthers dominate possession and spark a run of 10 unanswered goals at one point.

While Carney was the only player on all three teams, many of the Panthers got to enjoy their second title celebration of the year. Coach Ian Healy credited the coaching continuity between the three sports for fostering a culture of success.

Healy is also an assistant on the football team, and Levi Franklin — the school’s head basketball coach — helps out with both the football and lacrosse teams. Several assistants work on more than one staff, as well.

“It was three different families — all similar but completely different,” said Carney, who plans to play lacrosse at St. Mary’s (Md.). “It’s really special to share it with all the different guys I’ve won with.”

Potomac School senior Matt Carney, who scored three goals in the Panthers’ MAC championship game win, also was part of the school’s title-winning basketball team. (John McDonnell/THE WASHINGTON POST)

Senior goalie Pat Farrell made 13 saves for Flint Hill.