It was a harmless looking hit as far as penalties go, but it sent Harvard co-captain Julie Chu reeling into the boards and left the Crimson without the services of the “best player in college hockey” for the final period of Saturday’s game and likely for the immediate future.

With 2:25 remaining in the middle frame of Harvard’s second weekend clash with visiting Minnesota-Duluth, Bulldogs captain Noemie Marin brought Chu down with a tripping foul in the Crimson zone. Chu tumbled awkwardly to the ice, collided with the boards, and was unable to get up after the whistle blew. She rolled over several times and tried to get to her feet before her right leg gave out and she fell back down, bringing a hush over the Bright Hockey Center crowd of 906.

Teammates Lindsay Weaver and Caitlin Cahow rushed to her side and were quickly joined by the team’s trainer and coach, Katey Stone.

Chu was ushered straight into the locker room but returned to the bench on crutches for the third period, wearing sweats and a complicated wrap on her right ankle. But the senior center seemed in good spirits throughout the final 20 minutes, giving hope that the injury is not very serious, and appeared especially elated after Sarah Vaillancourt banged home the fourth score of Harvard’s 4-0 win. Vaillancourt headlines the group that must hold down the fort in the absence of Chu, who must be considered the early frontrunner for the Patty Kazmaier Award, given annually to the top female player in the collegiate ranks.

“I’m impressed with how our kids fill holes when somebody goes down,” Stone said. “The best player in college hockey went down in the second period and we filled that hole.”

Stone offered the diagnosis after the game.

“Sprained ankle,” Stone said. “You have to wait a day or two to see what happens. I don’t imagine that she’ll be playing [tomorrow] night [at UConn].”

GOALIE-ORIENTED

The Harvard-Duluth series featured not two, nor three, but four of the top goalies in women’s hockey.

The weekend opener pitted Crimson sophomore Brittany Martin against Bulldogs rookie Kim Martin (pronounced mar-teen). The UMD freshman is no stranger to top competition, however, having started in net for Team Sweden at the Winter Olympics in February. The Stockholm native led her country to a stunning semifinal win over the U.S. squad, which incidentally included Harvard stalwarts Chu and Cahow, at the tender age of 19.

“It’s not easy for international players to come here, not knowing that much English,” said Vaillancourt, who hails from French-speaking Quebec. “I know what she’s going through. She’s awesome.”

But it was the Crimson’s Martin who got the better of the battle, allowing only one goal on 20 shots in a 3-1 win. Her counterpart made 30 saves but came away with the loss.

At the close of play for the weekend, the two Martins stand second and third in the country in save percentage. Kim ranks No. 2 at .946; Brittany comes in third at .940.

Then, on Saturday, the Bright Center crowd got its first look at highly regarded Harvard freshman Christina Kessler, who missed the first three weeks of the season with a knee injury and has split time with Martin since her return. Kessler continued her impressive debut, posting a shutout for the second time in three career starts, stopping 20 shots in the process.

“It’s good to have two goalies that can go at any single time,” Brittany Martin said. “And internal competition it pushes us a lot.”

After the Bulldogs’ Martin allowed three more goals in the first two period of her Saturday start, she was replaced by senior Riitta Schaublin, the UMD starter in years past, for the final frame. Schaublin made nine saves and permitted only the Vaillancourt clincher.

“I’ve never been in this situation when I’ve been at Harvard to have two goaltenders that you could basically flip a coin on a given night and they’re going to give you a solid performance,” Stone said. “I feel very appreciative of that.”

“They’re two of the best goalies in college hockey,” she added. “How could you have one on the bench?”

WHISTLE BLOWER

In a tightly officiated set of games, Harvard’s familiarity with the East Coast referees and awareness of the recent rule changes might have made the difference. Over the course of the two games, Duluth was whistled for 23 infractions, while the Crimson went to the box only 11 times. And its edge in man-advantage time was not in vain, either, as Harvard cashed in five power-play scores combined over Friday and Saturday.

“I think everyone’s adjusting to the new officiating requirements,” Cahow said. “With both these teams, all the players are so fast and so strong, you’re going to have a lot of contact, it’s just playing hard. And last year, two years ago, it might not have been called as tightly as it was today, but we’re all adjusting.”

“I think he’s pretty consistent on the type of game that he calls,” said Stone, referring to Friday night zebra Dean Gilbert. “I don’t know if they’re used to that.”

IN OTHER ACTION

Even though the Crimson extended its nation-best winning streak to eight games in sweeping a Top 10 squad, don’t expect a bump in the new rankings, as all the top teams took care of business this weekend. No. 1 Mercyhurst took two games from Princeton, the second victory a 1-0 overtime nail-biter on Saturday, in which the Lakers outshot the Tigers, 48-9. In the ECAC, St. Lawrence, Clarkson, and Colgate all picked up two wins apiece. No. 3 New Hampshire notched one “W,” and No. 4 Minnesota won a pair. The most intriguing result came courtesy of Harvard’s next opponent, UConn, which knocked off No. 9 BC on Saturday, and could replace Princeton or the Eagles in the new poll issued today.

—Staff writer Jonathan Lehman can be reached at jlehman@fas.harvard.edu.