BOYLSTON — The defending Division 1 golf champions weren’t quite ready to surrender their throne on Monday at The Haven Country Club.

On a picture-perfect day for golf, the St. John’s (Shrewsbury) Pioneers put forth their ‘A’ game and dominated from the opening tee shot.

Led by individual medalist Ronan Mooney’s spectacular 4-under par 68, the Pioneers put four golfers in the top 13 positions as their team total of 6-over 294 bested Catholic Conference rivals Xaverian (303) and St. John’s Prep (306) for a second straight title and sixth since 2006.

It also marks the 13th time in 16 years that a Catholic Conference team has worn the Div. 1 crown.

For the Pioneers, however, Monday was not just about keeping the crown, it was about winning a title to lift the spirits of JV coach Tim Williams, who is fighting cancer.

“Tim and I started this program 11 years ago and he texted me early this morning that he was kicking cancer’s butt and he told the kids the same thing (Monday),” St. John’s coach Sean Noonan said. “To be able to win back-to-back is something extraordinary and to do it with three new players is special.”

The Pioneers were never behind as a team on Monday as Mooney, Adam Trani, Savar Bhasin and Cael Duggan combined to make 14 birdies and two eagles.

Perhaps no one was in more of a zone Monday than Mooney was.

His first shot of the day set the tone when he drove the first green to set up an easy birdie. It proved to be the first of a five-birdie-in-six-hole stretch to begin the round.

He later eagled the par-5 14th to push his score to 5-under before a bogey at 17 led to a 4-under round, one off the state individual record of 67 by Brookline’s James Imai.

“It’s really cool to cap off my high school career like this,” Mooney said. “We wanted to repeat what we did last year and we were successful in that. But this was bigger than golf. We wanted this for Coach Williams.”

About the only person who could rival Mooney’s blazing start was teammate Adam Trani. Playing on his home course, Trani birdied 14, 15 and 16 before dunking his approach to the 18th for an eagle to close out a round of two over 74. Savar Bhasin shot 75 and sophomore Cael Duggan added a 77 as the final scores the Pioneers counted.

Xaverian was led by rounds of 75 from Thomas Constantine, Michael McCormack and Sam Keyser in a run to second place.

St. John’s Prep got solid rounds of 74 from Seamus O’Halloran, 75 by Tripp Hollister and 76 from AJ Bednar as part of their 306 total.

“I think we play in the best league in the state in the Catholic Conference,” Noonan said. “It gets you ready to play at a high level. But this has been a crazy run. Second, first and first. It’s amazing.”