AYER — They say to beat a team three times in a season is the hardest thing to do in sports. For the Bromfield co-op team, comprised of Ayer Shirley, Parker Charter and Maynard, it looked at halftime that the old adage was going to prove true.

But the Trojans turned on the jets in the second half, erasing a three goal deficit, and pulled away in the fourth quarter as seventh-seeded Bromfield defeated tenth-seeded Lunenburg by an 11-9 margin on Tuesday night at Ayer Shirley Regional High School in the Division 3 Central East boys’ lacrosse tournament.

Bromfield (12-7) advances to take on neighboring Littleton High, the two seed, in the quarterfinals. Lunenburg, which was senior heavy, ends its season at 13-6.

Lunenburg went into the locker-room with a quality 7-4 lead and spirits were high. But Bromfield soon changed the momentum of the game to start the second half.

Jackson Ehwa scored less than a minute into the second half, when he darted to the net through traffic. Less than a minute after that, Sam Hills scored in transition, cutting the once lead down to 7-6.

Lunenburg veteran Declan Fitzpatrick stopped the cold spell , but then Bromfield’s Hills took a little shuffle on a nice cycle and buried it tying the game at 8-8 at the end of the third quarter.

Lunenburg committed five penalties in the fourth quarter. With 8:01 left in the contest, scored on a drive to the left post on the man-up. Less than a minute later, Fan Miller netted another man-up goal, which made it 10-8 Bromfield, a lead it would sustain until the end.

“We’ve played a hard schedule so we’re used to playing a full game,” Bromfield co-op head coach Patrick Frederickson said. “Our games with Lunenburg are always great, the first the winning goal came with four seconds, the second went to double overtime. So we never worry about the score at halftime.

A lot of what we’re running, we want to tire teams out. We weren’t really too concerned about being down three goals at halftime.”