LYNN — Every seat that could possibly be filled inside the Tony Conigliaro Gymnasium on Tuesday was occupied some 35 minutes before St. Mary’s and Lynn Classical battled for a spot in the Division 3 elite eight.

And befitting the atmosphere, the  teams battled tooth and nail through the first 16 minutes before the top-seeded Spartans, led by J.J. Martinez, put the hammer down.

The Spartans (21-1) outscored Classical 44-27 in the second half to cruise to a 75-54 win and a quarterfinal berth.

“That atmosphere was unbelievable in the first half,” St. Mary’s coach David Brown said. “The third quarter was huge for us. I was happy to see us come out and play the way we did to take control of the game.”

The Rams (17-5) met the hostile atmosphere well in the first half as they turned an early 10-point deficit into a four-point game at halftime thanks to the play of DJ Reynolds and Rolky Brea Arias, who combined for 23 points and helped off set 12 points from Martinez.

The third quarter, however, would belong to the Spartans.

Martinez and Jake Fortier did most of the damage in the first four minutes as the Spartans blew out of the locker room on a 12-2 run that forced a Classical timeout.

Reynolds momentarily stopped the run for Classical, but Gabe Sykes responded with a three that made it a 15 point margin and had the Rams trying to play catch up the rest of the way.

The Rams kept battling but could never get the margin under 14 in the final quarter and a half as the Spartans eventually grew the margin to as much as 19 before the starters departed the floor in the final minutes.

“We really felt that their big guy (Arias) was going to have to beat us,” Brown said. “And we did a really good job on him in the second half.”

Another critical contribution for the Spartans came off the bench as June Vasquez chipped in 15 points, half of them coming in the second quarter when Classical was in the midst of rallying from 10 down.

“June is our best shooter and it lets us spread the floor because we’ve got two or three guys that can score when he’s out there,” Brown said.