TOWSON, Md. — Boston College’s defense was supposed to be its Achilles’ heel — a patchwork unit of two freshmen, a sophomore and a former walk-on. A shootout, it seemed, would be the Eagles’ path to their fourth straight NCAA championship game.

Goalie Rachel Hall had other ideas.

Hall saved her best performance of the season for the biggest stage Friday, making one spectacular save after another and neutralizing top-seeded North Carolina in an 11-10 NCAA semifinal victory in front of a sold-out, 50-percent max capacity crowd of 5,100 at Towson’s Johnny Unitas Stadium.

“It’s definitely surreal,” said Hall, who transferred to Boston College after leading the NCAA in saves as a freshman at Oregon in 2019. “It’s something that I’ve dreamed about my whole life. But I’ve dreamed about winning a national championship. We have another game to play.”

The fourth-seeded Eagles (17-3), a three-time NCAA runner-up from 2017-19, will play Syracuse in the championship game Sunday at 12 p.m. Eastern (ESPNU). The Orange advanced by way of a 21-13 win over previously unbeaten Northwestern.

BC advanced despite going scoreless over the final 15 minutes and getting a relatively subdued game out of star attacker Charlotte North. The Eagles knew exactly who to thank for that, emptying the bench on the opposite side of the field and sprinting to embrace Hall, who outdueled Tewaaraton Award finalist Taylor Moreno.

Hall’s masterpiece featured a mix of splitting kick saves, off-stick stops with her hips and shoulders and free-position denials. She finished with 11 saves, the box score saying nothing of the degree of difficulty in the shots she faced.

UNC came in shooting nearly 50 percent for the season but shot just 10-for-35 (28.6 percent) against Hall, who came in saving fewer than 40 percent but stopped 11 of 21 shots on goal (52.3 percent).

“I didn’t think that I had the best season up to this point, but they stuck with me,” Hall said. “They knew that when we got to this stage, I’d be prepared.”

Boston College snapped North Carolina’s 27-game winning streak, which dated back to the last time BC beat UNC — an instant-classic 15-14 double overtime triumph less than five miles from here at Johns Hopkins’ Homewood Field in the 2019 NCAA semifinals.

“It’s become a big rivalry between our two teams, which is something we’ll always cherish because Carolina has such a rich tradition,” Eagles coach Acacia Walker-Weinstein said. “Every year, we’re building on the tradition that we have.”

UNC led 4-2 in the early going. But Jenn Medjid scored three of her game-high four goals during a four-goal BC run to give the Eagles a lead they never relinquished.

North, of course, also had a hand in it. The Tewaaraton finalist scooped a ground ball one-handed and ripped a knee-level sidearm shot on the run past Moreno, setting BC’s single-season record with her 95th goal.

The Eagles led 8-5 at halftime and stretched the lead to five in the second half. Medjid’s free-position goal with 15:27 remaining put BC ahead 11-6.

That’s when the Tar Heels (20-1), buoyed by a decisive advantage in draw controls (16-for-23) made their run. They scored two straight and then cut the deficit to two when Katie Hoeg isolated mismatched midfielder Phoebe Day on the left wing and scored to make it 11-9 with 5:07 remaining.

Nineteen seconds later, Elizabeth Hillman got an open lane to the goal. She tried to tuck a shot across her body and inside the near pipe, but Hall stood her ground to make the save.

Jamie Ortega, yet another Tewaaraton finalist in this star-studded semifinal, also had a chance to pull UNC within one. But on one of the few occasions that freshman defender Sydney Scales lost sight of her, Ortega rang a shot off the post with 2:31 left.

UNC maintained possession, but Ally Mastroianni shot high and then Hall, again ranging to her off-stick side, denied Scottie Rose Growney with 1:53 remaining.

“Rachel is an unbelievable goalie. The game ball goes to her,” Medjid said. “Just seeing her make those ridiculous saves, it just pumped up me and all of our teammates for us to finish the job.”

The Tar Heels picked up two yellow cards in the final 90 seconds and the Eagles killed enough clock to ensure that Mastroianni’s man-down goal that made it 11-10 with 1.3 seconds left did not leave UNC with enough time to complete its comeback.

Caitlyn Wurzburger and Hoeg were the lone bright spots for the Tar Heels offense, each finishing with three goals and an assist. Otherwise, UNC found tough sledding against a BC defense that came in ranked 42nd nationally and surrendered 21 goals to the Tar Heels in a 21-9 loss March 6.

The Eagles defense — anchored by two freshmen down low in Hunter Roman and Scales, a sophomore up top in Hollie Schleicher and redshirt junior Melanie Welch assigned to Hoeg —  clogged the interior and slid effectively. Scales limited Ortega to just one goal and midfielder Belle Smith caused two turnovers to go with a goal and an assist.

“I just thought we were a little impatient today, and it played into what BC was doing defensively,” North Carolina coach Jenny Levy said.

UNC’s shooters were frustrated by Hall, who along with the other goalies on BC’s roster has benefitted from the tutelage of a former UNC star in Billy Bitter, Walker-Weinstein said. The Eagles brought on Bitter as a volunteer assistant this year specifically to work with the goalies.

“He’s a great coach who has an incredible perspective on goaltending being one of the best shooters ever,” she said. “They’re putting in hours and hours extra studying shooters, studying stats, tendencies and patterns. ... It all kind of came together today.”

Boston College lost to Maryland in the 2017 and 2019 NCAA finals and to James Madison in the 2018 final. Walker-Weinstein knows better than to get too high after Friday’s upset of North Carolina, adding she learned from those experiences the value of recovery, film and a fresh scouting report with a short turnaround.

“A lot of the things our staff wanted to be better at [in past championship weekends], it starts right now,” she said. “I’m just grateful to have a chance to error-correct.”