Once Joe Calvello won the opening faceoff in overtime, it appeared the Massachusetts men’s lacrosse team was on its way to a sloppy victory.

Calvello brought the ball into the offensive zone, and passed it out to Connor Mooney. Mooney then swung the ball around before being set up for a scoring chance that was denied in front of the net by Brown’s zone defense.

Andrew Sokol tried to get the ball out to Bobby Tyler but the pass was deflected by Sam Ford. Ford grabbed the loose ball and found Daniel Mellynchuk, who then raced into the offensive zone and fired a shot past Zachary Oliveri to give the Bears a 9-8 victory in front of 1,036 at Garber Field on Saturday.

It was UMass’ first regular season loss since a 14-5 defeat to Hofstra on April 23, 2011.

The No. 5 Minutemen (3-1) committed 16 turnovers for the game, but it was the final one that sunk them in the end.

“(Brown) had great focus, better focus than us,” UMass coach Greg Cannella said. “We weren’t sharp mentally at any point in the game.”

UMass led 8-5 with 7:11 remaining in the game after Grant Whiteway completed a hat trick on a man-up goal. But Kylor Bellistri single-handedly brought Brown (1-1) back into the game with three unanswered goals in a matter of three minutes to knot the score at 8-8, which is how it remained for the rest of regulation.

The Bears controlled the pace of the game, forcing the Minutemen out of their up-tempo style by packing bodies in front of the net and playing a zone defensively.

“(The zone) forced us to be (slower) on offense, great coaching move,” Cannella said. “They controlled the pace, we played a lot of defense again. We’ve been doing that in all of our games, and that’s not a good formula.”

UMass was taken out of its offensive rhythm for a majority of the game, but finally found it with 2:34 left in the third quarter when Matt Whippen found Andrew Sokol to tie the game at 4 a piece.

Calvello won the ensuing faceoff and took it in himself to score his first goal of the season and give the Minutemen their first lead since going up 2-1 late in the first quarter.

Mooney seemingly put UMass in control with his lone goal of the contest to make it 6-4. Momentum was in favor of the Minutemen heading into the final frame, but Brown quickly took it back when Alex Jones cut it in half with 12:36 left in the quarter.

The Bears struck first when John DePeters scored a man-up goal with 7:07 left in the opening quarter. DePeters received a pass from Bellistri from the top of the box and rifled it past Oliveri.

UMass didn’t take long to tie it up as Matt Whippen scored his team-high ninth goal of the season less than a minute later. The Minutemen then took the lead at 4:08 when Kyle Smith’s shot hit off the top of the post, and Whiteway scooped up the rebound and scored into an open net.

That would be the last time UMass scored in the first half.

“We came out sloppy,” Smith said. “On offense, our thing is that when we play together, we play better. We just weren’t playing together (Saturday). And that was everyone. It’s pretty frustrating.”

Oliveri made 15 saves in a losing effort, his first career defeat in goal. Brown outshot the Minutemen 46-30 for the game, much of that as a result of UMass’ poor effort offensively.

“I don’t have the answers,” Cannella said. “Teams are playing us a little bit differently the last two games. Our midfielders and our attack have to handle the ball a little bit better. There’s no excuse to throw a 10-yard pass at someone’s feet in my opinion.”

With two of its better offensive players in Will Manny and Colin Fleming still out with injuries – neither are expected to play Tuesday at Albany – UMass has been reliant on younger players to step up and fill these scoring roles.

However, Cannella doesn’t see that as a valid excuse for the Minutemen’s offensive struggles in the last two games.

“You can’t make excuses,” he said. “When you schedule the games and you play the games, you play with the people you have.”

Smith echoed his coach’s sentiments.

“Those guys are good players, they help, but we have a team of 40 guys, those players are good too,” Smith said. “Those two guys aren’t our entire team. We have good players, and today on offense we did not play well as a team. I’m glad we have a game Tuesday.”

UMass will look to get back to its winning ways against the Great Danes at 3 p.m. on the road Tuesday.

Nick Canelas can be reached at [email protected] and followed on Twitter @NickCanelas.