Junior Sarah Vaillancourt tallied a pair of goals while Harvard was at a man disadvantage, scoring on a Cornell power play in the first period to give the Crimson a 1-0 lead, then adding an empty-net goal in a 6-on-5 situation that made the final score 4

It wasn’t the easiest of victories for the No. 1 Harvard women’s hockey team, but it was an important one. The Crimson (29-1-0) defeated Cornell (12-19-1), 4-2, Saturday evening at Bright Hockey Center to sweep the conference quarterfinal series and punch its ticket to the ECAC semifinals.

“It was a battle, we knew it was going to be a battle,” junior forward Sarah Vaillancourt said. “We knew we had to come out hard.”

Junior Sarah Wilson scored the game-winner just 15 seconds into the third period, when she took a pass from classmate Jenny Brine and broke away toward the Big Red’s net.

Although Cornell goaltender Jenny Niesluchowski saved the first shot, Wilson took control of her own rebound and beat Niesluchowski for the eventual game-winner.

Unlike Friday night’s game, Harvard jumped out to an early lead and held onto it the whole way.

While on the penalty kill a minute into the game, Vaillancourt got the puck from senior tri-captain Caitlin Cahow and streaked up the ice.

With two Big Red defenders in her wake, Vaillancourt faked out Niesluchowski before finding the back of the net for her third short-handed goal of the season.

“That’s what she does,” head coach Katey Stone said. “She’s a threat when she’s on the ice all the time. The thing that I’m most impressed with is how well she plays in all three zones, and that’s what’s helping our team most.”

Both teams would have their fair share of scoring opportunities in the opening period, with seven penalties called in the first 20 minutes of play, but neither the Crimson nor Cornell could capitalize.

But it was another penalty, this one on the Big Red’s Amber Moore, that led to Harvard’s second goal of the night.

The Crimson waited until the last seconds of the power play to strike. Freshman Liza Ryabkina put the puck in play in front of the net from the blue line, and it was Cahow who was able to bank a shot off the post into the net.

Ryabkina and junior Kati Vaughn nabbed assists on the play.

Now up 2-0, Harvard was forced to go on the defensive.

Brine was called for holding at 7:15 in the second, and the Crimson would be shorthanded for the following 5:45. Cornell found the back of the net only once during that span, on a 5-on-3 advantage at 9:10.

Ivy League Rookie of the Year Rebecca Johnston launched a shot that ricocheted off the post, leading to a flurry of shots from the Big Red offense. It was sophomore Liz Zorn who finally put the puck past Harvard goalie Christina Kessler, with assists coming from Johnston and Sam Wauer.

But the Crimson would hold off the Cornell attack for the remaining four minutes of shorthanded play, keeping the score 2-1 heading into the second intermission.

“We want them to call a tight game because that suits our game,” Stone added. “We had to kill more penalties than we would have liked, but we also had plenty of power play chances too.”

Harvard jumped out to a 3-1 lead on Wilson’s goal, but it didn’t take long for Cornell to retaliate.

Less than a minute later, Big Red freshman Hayley Hughes beat out Kessler and cut the Crimson’s lead to 3-2. Cornell co-captain Brittany Forgues got the assist.

The teams traded penalties again in the third, with four being called in the span of 90 seconds. But it was defense that was the story of the final period.

Niesluchowski made 16 of her 49 saves in the third frame, and Kessler responded with 10 of her own en route to a 27-save effort.

The Big Red pulled their goalie with 1:24 to play, but failed to keep the pressure in the Harvard zone. Vaillancourt stole the puck and put it into the empty net with 39 seconds left, bringing the final score to 4-2.

“It’s important for us to be able to play 6-on-5,” Vaillancourt said. “Then being able to score too—that just killed them right there.”

With the win, the Crimson advances to the ECAC semifinals, which will be held at Bright next Saturday. Harvard will play the winner of the Clarkson/Princeton series.

“I’m really happy. I thought the kids played hard both nights,” Stone said. “It was certainly another good test for us as we’re going into the playoffs. We haven’t had tons of really tight games all year so this is good for us right now.”

“We’re just really excited that we will be hosting, playing in front of our fans,” Vaillancourt added. “This is going to be a really good week for us, of hard practices and just getting ready for whoever we’ll play.”

—Staff writer Kate Leist can be reached at kleist@fas.harvard.edu.