The Terrapins women’s lacrosse defense allowed Penn to take 21 shots when the teams met in the regular season in March, but the Quakers found the back of the net five times in a 10-goal loss.

In the opening 30 minutes of the second round of the NCAA tournament yesterday, though, Penn shot 50 percent, and the Quakers scored four goals during the half.

But in the second period, the No. 1-seed Terps clamped down. They limited Penn to one goal in the second half to polish off a 13-5 win at the Field Hockey and Lacrosse Complex, sending the Terps to a quarterfinal matchup with Duke on Saturday.

“It was nice to see us kind of improve and make some adjustments at halftime to limit their opportunities in the second half,” coach Cathy Reese said.

Though the Terps never trailed Penn in the regular-season contest, the Quakers scored the first goal yesterday less than five minutes in.

And with attacker Halle Majorana, who entered the game ranking sixth on the team with 20 goals, absent from the Terps lineup for an undisclosed reason, Reese adjusted her offensive game plan.

But attacker Kristen Lamon was first off the bench for the Terps — a role Majorana usually fills — and quickly made an impact. Lamon cut in from the right side of the goal and finished off the shot in the top-right corner in the 10th minute to give the Terps a 2-1 advantage over the Quakers.

After the Terps scored two more goals in the next minute, they turned the ball over, allowing Penn a chance to end their four-goal run. The Quakers cleared the ball with 19:03 remaining, and the Terps defense repeatedly forced Penn to circle the net, not allowing a shot for more than four minutes.

Eventually, though, Quakers midfielder Tory Bensen beat goalkeeper Abbey Clipp with 11:38 left to end the seven-minute possession.

“Our defense played great for six-and-a-half minutes, seven minutes and then one slip-up,” midfielder Taylor Cummings said. “We just need to keep focus and keep our attention spans when teams are going to do that.”

The Terps won the next draw control, but Quakers goalkeeper Lucy Ferguson made a save 10 seconds later, to give the Quakers a possession that led to a goal, cutting the Terps lead to 4-3.

But that is as close as the game would get. The Terps defense limited Penn to one goal in the final 10 minutes of the half, and the team won all but one draw control during that time to go on a 4-1 run before halftime.

Despite the 8-4 lead, Reese wasn’t happy with the Terps’ first-half defense and made adjustments during the break.

“We were playing pretty poor defense in the first half,” Reese said. “We were giving up drives on one on ones, and we needed to tighten that up.”

The Terps defense held the Quakers scoreless for the first 10 minutes of the second half before Bensen scored her third goal of the contest.

But instead of allowing Penn to climb back into the game, the Terps defense locked down and forced seven turnovers in the second half.

The Terps held the Quakers scoreless for the rest of the game, limiting them to four shots in the second half. With the Quakers offense shut down, the Terps scored the final four goals of the contest to secure their spot in the quarterfinals.

“In the second half, we just got stronger and tougher as a whole, not just one or two people,” midfielder Kelly McPartland said.