And just like that, it’s over.

A once promising 2012-13 season came crashing down on the Massachusetts men’s basketball team Wednesday night in its 71-58 loss to Stony Brook in the first round of the National Invitation Tournament in front of 2,173 at the Mullins Center.

UMass (21-12) looked disinterested for most of the game, playing careless on the offensive end by settling for 3-pointers early in the shot clock and throwing away possession after possession as the Minutemen didn’t come out with the same fire or demeanor as they had in last week’s Atlantic 10 Tournament in Brooklyn.

The Minutemen had 19 turnovers — most attributed to sloppiness — and shot just 6-for-26 (23.1 percent) from 3-point range.

“I thought we played better and harder against teams in Brooklyn than we did tonight,” UMass coach Derek Kellogg said. “It was a quick turnaround, a lot of emotions flowing around for a couple of days and you had a hungry team that played well. That usually bodes for not being very successful.”

The Minutemen were left out of the NCAA Tournament Sunday night after not earning an at-large bid. Instead, they were sent back to the NIT for the second year in a row, but didn’t bring the same intensity as last year’s squad that made it to the NIT Final Four.

The Seawolves (25-7) trailed by four with seven minutes, five seconds left in the first half, but a hard foul by Cady Lalanne on a screen jumpstarted Stony Brook to a dominating 17-0 sprint to close out the half and take complete control of the contest at 38-25. In that span, UMass committed seven turnovers, missed all five of its shots and burned two timeouts to try and stop the bleeding.

Kellogg described the sequence as “terrible.”

“We had all sorts of miscues and they had all sorts of good plays,” he said. “I think I used a timeout or two in there, we had the ball a few times right around the rim. I think we took a lot (of) more tough, bad shots tonight than we had taken in a while. That attributed a lot to our scoring drought.”

Freddie Riley, who played in his last game as a Minuteman, said the team felt good heading into the game despite the disappointment of not making the Big Dance.

“We had a lot of energy in the locker room, I really don’t know what happened once we got on the court,” he said. “Our energy just wasn’t where it needed to be and Stony Brook just took it to us.”

Terrell Vinson also played in his final game at UMass, finishing with 11 points and five rebounds before fouling out with 4:34 left.

Chaz Williams’ impact was virtually nonexistent after only logging 16 minutes — his lowest total of the season — while nursing foul trouble in the first half and didn’t play the final 14:08 after suffering a mild right shoulder strain from getting tangled up in a screen just five minutes into the second half. The junior went into the tunnel with an ice pack on his shoulder, but returned to the bench with less than eight minutes to go with a towel over his head.

He finished with a season-low two points on 1-of-3 shooting, but managed six assists against five turnovers.

In Williams’ absence, Trey Davis had two points (1-of-9 shooting), six assists and two turnovers in 26 minutes.

Kellogg doesn’t believe Williams’ fewer minutes was the sole indication of the loss, saying that he “wasn’t playing great at the time,” but did acknowledge the negative effect it had on setting up the offense.

“You could see where we struggled with some fundamentals of basketball without him in the game as our primary ball-handler,” Kellogg said. “And anytime you miss the first team conference guy who scores 20 a game, I mean obviously that’s gonna have an effect on the ball club, which I believe it did.”

UMass came out in the second half with the urgency it lacked in the first and cut the deficit to six on a Freddie Riley layup with 7:44 to go. But Anthony Jackson drilled a jumper in front of the SBU bench the next trip down to push the lead back up to eight and ignite a 6-0 run to take back command at 63-51.

Jackson was on fire from the opening tip, finishing with 20 points on 8-of-10 shooting, including 4-of-5 from downtown.

Riley, a senior, led the sub-par Minutemen production with 16 points on 6-of-13 shooting, and surpassed the 1,000-point milestone with a triple with 17:07 remaining. He ended his UMass career with 1,006 points.

Stephen Sellner can be reached at [email protected] and followed on Twitter @Stephen_Sellner.