Video by Cal Borchers for Boston.com

By Anthony Gulizia, Globe correspondent

WORCESTER – Trying to predict who will lead the St. John’s Prep Eagles in scoring is like trying to predict New England weather – impossible.

Steve Haladyna finished with a game-high 29 points to lift the Eagles (25-1) over St. John’s of Shrewsbury (21-4) 72-57 to capture the Division 1 state championship at the DCU Center last night.

The junior guard exploded for 17 points in the third quarter and single-handedly drained the life out of the Pioneers.

“We made it a point at halftime to get out and run,” Haladyna said. “We wanted to make it a fast-paced game and just push it on them and get fastbreak points.”

Haladyna’s run started when he opened up the half with a jumper, followed by a 3-pointer to give the Prep a 33-21 lead.

Junior Owen Marchetti, who finished with eight points, added another to give the Eagles a 35-21 lead.

With 2:11 remaining in the half, Haladyna knocked down another 3-pointer to give his team a 52-34 lead.

Senior Richard Rodgers, who finished with 26 points, tried to keep his team close, but Haladyna refused to let the Pioneers get close.

“[Haladyna] is a big time player,” Prep coach Sean Connolly said. “When people key in on Pat [Connaughton], he’s tough. He has an array of shot’s, he can hit 3-pointers and floaters and he’s just a tough cover.”

Connaughton, who finished with 25 points and 12 rebounds, was satisfied with his performance, but all his praise was for his teammate.

“He’s been the second-hand guy ever since he came up,” Connaughton said. “And that’s really what sparks us – he’s another weapon. I told him coming out of the locker room at halftime that it’s going to be the last time I play with him in a St. John’s Prep uniform, so let’s make it a memorable one.”