CARY, N.C.North Carolina had its eyes set on a monumental comeback Saturday, but so did Duke’s Hanna Mar.

Advantage, Mar.

The senior battled back from a set down and a 5-3 deficit in the third set before ultimately prevailing 3-6, 6-1, 7-6 (7-4) against Caroline Price to give No. 6 Duke a 4-3 victory against its local rival at Cary Tennis Park in Cary, N.C., advancing the Blue Devils to the ACC tournament final Sunday.

"At the finals of the National Team Indoors, it came down to [Mar]," Blue Devil head coach Jamie Ashworth said, referring to Duke's 4-3 victory against UCLA in February. "Having her on the court and having someone that's been in that position before, in a situation like this, is great."

Duke’s win is its third in as many days at the ACC tournament as well as its third this season against No. 11 North Carolina, the top seed in the tournament. However, the match Saturday was much closer than the previous two showdowns, as the Tar Heels (25-5, 13-3) overcome a 3-0 deficit in the match to tie the Blue Devils (24-3, 14-3) at 3-3.

Surrounded by their teammates and a swarming, bipartisan crowd, No. 35 Mar and North Carolina’s Price squared off in the deciding match at third singles. Mar had knocked off No. 50 Price in straight sets earlier this year at home, but a rougher start Saturday, struggling in the opening set before finding some momentum in the second.

"I wasn't playing at the beginning the way I needed to to win that match," Mar said. "So it was really important for me to make changes to the way I played, and I think I did that really effectively in the second set."

As both Mar and Ashworth emphasized, the key to Mar's turnaround was her more aggressive play, beginning in the second set.

"That first set she sat back and kept waiting for [Price] to miss. And I said to her, 'You gotta come in. You gotta move forward,'" Ashworth said. "She won those two games [at 2-1] in the second set, and six out of eight points she came to the net. She did a great job of changing her strategy and adjusting what she was doing and correcting what she didn't do right in the first set."

Elysia Su / The Chronicle

In the third set, Mar continually played from behind and was three points away from losing the match at numerous junctures. Still, she remained rock-solid mentally, clawing ahead in the tiebreaker and then clinching the win on her second match point.

"It's just the knowledge that it's not finished until it's actually finished," Mar said of having to battle back. "So I just had to keep going. And I had great support from my teammates and the people around watching, who I just knew were still with me and believed that I could win that match."

The start was auspicious for the fifth-seeded Blue Devils, who played some impressive doubles at the third and first positions to claim the requisite two victories for the doubles point. Junior Annie Mulholland and freshman Chalena Scholl, ranked 88th nationally, gave the Blue Devils an early lead with an 8-3 win against Laura Slater and Kate Vialle, the No. 51 team in the country. Duke fell at second doubles, where Ashley Dai and Jamie Loeb topped the 30th-ranked pair of junior Ester Goldfeld and freshman Alyssa Smith by the same scoreline.

The doubles point came down to Mar’s court, where the senior played first doubles with Beatrice Capra against Price and Whitney Kay, the 10th-ranked pair in the nation. The fifth-seeded Blue Devils duo trailed at 4-5, but starting with a tough hold by Capra, the pair rattled off four of five games to claim the 8-6 advantage and the opening point. Mar and Capra's rally was a product of repeated small-scale triumphs, with the team gaining slim advantages in each game and riding those to victory.

"Something that we've talked about is trying to not play from behind," Ashworth said. "For Hanna and 'Trice, the more that they can be up 30-love, 30-15, [the better]. Because Hanna plays a little bit riskier...so to get yourselves up to begin the game, that's a really big thing. And that return game they played at 6-all was one of the best return games they played the entire match."

It was the third consecutive win for Duke’s top doubles squad and the third straight match in which the Blue Devils have claimed the doubles point. But the momentum didn’t translate to singles, as the Tar Heels seized four of the six opening sets with relative ease.

Despite the slow start, Duke took a 3-0 lead following victories by redshirt junior Rachel Kahan against Vialle at sixth singles, 6-1, 6-2, and Scholl, who defeated Kay 6-4, 6-3. The win was Scholl's third in three days at fourth singles. But without a comeback win on one of the four remaining courts, the Blue Devils would not be playing Sunday.

North Carolina proved to be too tough at the top of ladder, as No. 5 Hayley Carter overwhelmed No. 26 Goldfeld at second singles, winning 6-3, 6-4, and No. 1 Loeb dispatched the seventh-ranked Capra on court one, 6-3, 6-3.

At fifth singles, No. 113 Smith shook off a rough first set and rallied to force a second set tiebreak against No. 111 Dai. Once there, though, Dai cruised, taking the final four points of the tiebreaker to claim a 6-2, 7-6 (7-2) victory and square the match at three-all.

"Alyssa's had some really good wins for us, [like] at team indoors when we were down 3-0," Ashworth said. "At that point, you're hoping to get it to a third set somewhere, when you're down on all four courts. Then anything can happen. And when you have Hanna on the court, literally anything can happen."

Mar managed to force a third set but didn't stop there, and her fight proved to be the difference Saturday. Duke’s reward will be the right to play its fourth match in four days Sunday, when it will take on the winner of the other semifinal between Virginia and Miami for the ACC tournament crown.

"We came in here a little bit unlucky, having to play four matches in four days," Ashworth said. "But hopefully we can use that to our advantage, gain some confidence, and go out and have a good effort tomorrow."