As the Lavietes Pavilion crowd sang “Happy Birthday” to co-captain Christine Clark at halftime, the senior cracked a smile and fittingly poured in a game-high 21 points on her 21st birthday. But one half later, spirits were not quite so high for the senior guard.

Though the Harvard women’s basketball team (2-1) earned another mark in the win column, the 76-67 victory over Boston University (0-2) was anything but gratifying. The Crimson, which opened up its season home opener on a 10-0 run, led by as many as 20 during the contest, including a 1- point lead at the end of the first half, yet struggled to maintain that edge during the second frame.

Despite never losing its lead, Harvard looked like a different team in the second half, as they let the Terriers crawl within six points with 1:40 remaining before calling a timeout.

“It wasn’t a good feel [during the second half],” Clark said. “Moving forward, I think that we need to take this as a lesson and sit down and figure out what went wrong because I can’t tell you right now.”

The Crimson dominated BU to start the night, as they forced the ball down low to junior forward Temi Fagbenle. Fagbenle showed an arsenal of offensive weapons, hitting a reverse layup and dishing out no-look-passes to amass two points and four assists before the Terriers could even blink.

As Fagbenle began to draw double teams, she opened the floor for Clark, who scored in double figures for her 75th straight game, and for sophomore guard Shilpa Tummala, who contributed a career-high 14 points, including three-for-five shooting from behind the arc. But Harvard moved away from its post game as the night continued, relinquishing its clear advantage in the paint.

“We should have been [getting the ball into the post] the whole game,” coach Kathy Delaney-Smith said. “I thought that our posts were showing their numbers early, and we had a ball screen offense, and they were open, but we didn’t see it.”

But the Crimson saw exactly what made them so successful in the first half disappear from the hardwood floor when they returned from the locker room break. After out-rebounding Boston University, 27-17, in the first half, Harvard finished the game with 38 boards to the Terrier’s 39.

“Not one aspect of the game carried over,” Delaney-Smith said. “Rebounding was just part of a complete implosion.”

After the Terriers cut the Crimson lead to 12 to start the half, it seemed as if Harvard had weathered the storm when they pushed the lead up to 20 with only six minutes remaining. But BU wouldn’t go away, as junior Mollie McKendrick and senior Whitney Turner each poured in 14 points to keep the game close.

Nonetheless, on her night, Clark would have none of it. After watching her team let the lead slip away, the veteran came back in and knocked down a tough fadeaway jumper with 4:30 remaining to put her team up, 69-56.

The Terriers still refused to go away, as McKendrick came up with a pair of jumpers to cut the Harvard lead to six with just under two minutes remaining. Though the BU press befuddled her teammates, Clark was unfazed.

With the game on the line, the senior was a one-woman press breaker. Clark dribbled through the Terriers’ zone press, attacked the basket, and nearly banked in a shot for a three-point play. Calm and collected, Clark then stepped to the line and swished both free throws to push the lead back up to eight.

Clark soon found herself right back at the charity stripe, where she knocked down another pair of free throws, putting a halt to the roller coaster ride of the second half.

“[Clark] is a phenomenal athlete, and we would certainly not have won tonight’s ball game without her,” Delaney-Smith said. “I think that she was one of the more consistent players…. She knows that we are looking for her skill to get us through the times where we weren’t connecting.”

While Harvard experienced its own second half woes, the Terriers were only able to shoot 36.8 percent from the field and managed to miss 13 free throws. The poor offensive performance was more the result of the Terriers’ stagnant offense, though Fagbenle did finish with two blocks and three steals.

Despite its poor second half play, the Crimson won their 15th straight home game, a streak that extends back to the 2011-12 season when they last lost to Princeton on their home court.