In this 2019 file photo, Eduards Tralmaks of the University of Maine looks to make a pass during a game in Orono. He scored a goal in Monday's loss at UMass Lowell. Credit: Peter Buehner photo

Junior defenseman Chase Blackmun registered his first career hat trick and the University of Massachusetts Lowell scored two second-period goals on Monday en route to a 9-5 Hockey East victory over the University of Maine at Tsongas Arena in Lowell, Massachusetts.

The River Hawks (3-1) completed a sweep of their two-game series with the Black Bears, who fell to 0-3-1. UMass Lowell won Sunday’s game 5-3.

It is UMaine’s worst start since losing its first four games in the 2014-15 season. It was the most goals allowed by the Black Bears since a 9-2 loss to Wisconsin on Jan. 10, 1986.

“Everybody shared in this,” UMaine head coach Red Gendron said. “At the end of the day, we needed to play better team defense. We needed better goaltending and we needed to pay better attention to detail in our systems.”

Gendron said his team needs to learn to handle adversity better, saying the players were barking at each other during the first two periods for mistakes that were being made.

He said the situation was discussed after the second period and didn’t occur in the third period.

“We need to support each other,” Gendron said.

The River Hawks erased two one-goal deficits during a wild, six-goal first period.

Blackmun scored 7:47 into the game, his first of the season, before UMaine’s Edward Lindelow answered just 27 seconds later.

UML’s Ben Meehan was assessed a five-minute major for hitting from behind at the 12:13 mark of the period and UMaine scored twice with the man advantage, but also allowed a shorthanded goal by Zach Kaiser.

Jacob Schmidt-Svejstrup gave UMaine a 2-1 lead before Kaiser responded only 20 seconds later.

Emil Westerlund restored the Black Bears’ one-goal lead at the 16:42 mark but Blackmun tied it up with an even-strength goal 1:02 later.

Blackmun started the scoring in the second period to give the River Hawks their second one-goal lead but Eduards Tralmaks tied it 3 1/2 minutes later with a shorthanded tally.

After Blackmun’s second goal, Gendron replaced freshman goalie Victor Ostman, who made his first collegiate start and made 13 saves on 17 shots. He was replaced by Matthew Thiessen.

Logan Neaton started for UMass Lowell but was lifted after the first period in favor of Rensselaer Polytechnic Institute transfer Owen Savory. Neaton made 14 saves.

Brown gave the River Hawks the lead for good on the power play. The Black Bears turned the puck over as it glanced off a UMaine skate and wound up on the stick of Brown, who was alone with a teammate in front of Thiessen.

Thiessen made a terrific initial save but the rebound squirted to his left and Brown shoveled it home during a scramble.

Brian Chambers expanded the lead with 2:09 remaining in the period when he was set up nicely by Lucas Candotta after a flurry in front and flipped a 12-footer into the open net.

Levi Kleiboer pulled UMaine within one with a screened wrist shot from the point at the 5:34 mark of the third period, but Brown’s one-timer from the left circle off a Berglund pass restored the two-goal lead 4:24 later. The River Hawks added insurance goals from Nik Armstrong-Kingkade and Lucas Condotta.

UMass Lowell outshot UMaine 58-30, including a 46-13 edge over the last two periods.

UMaine was without senior defensemen J.D. Greenway and Cam Spicer and captain Jack Quinlivan, a senior center, for the two-game set.

Gendron wouldn’t reveal why the trio was unavailable when asked after the game.

UMaine travels to Vermont for 2 p.m. games on Friday and Saturday.