NEW YORK - World No.18 Maria Sakkari ended 2019 US Open champion Bianca Andreescu's 10-match unbeaten streak in New York in the latest finish of a women's singles match at the US Open, winning 6-7(2), 7-6(6), 6-3 to advance to her second major quarterfinal of the season. The 3-hour, 30-minute battle ended at 2:13 a.m. The previous record was set in 2016 by Madison Keys and Alison Riske, which ended at 1:46 a.m.

Playing for the second time this season, Andreescu and Sakkari once again locked horns in a tense duel that was decided by just a handful of points. The duo faced off in the spring in the semifinals of the Miami Open, where Andreescu prevailed in a physically grueling 7-6(7), 3-6, 7-6(4) win. That match was filled with protracted rallies and variety, and both Sakkari and Andreescu seemed committed early to make their second meeting about high-octane offense.

"I told Tom [Hill] and my team before the match that I'm prepared for 7-6 in the third," Sakkari said. "Seriously, I never thought that with Bianca it would be like 6-4, 6-1 unless I played lights out tennis, hit winners left and right. But because she fights every single point, I knew that it was going to be a very tough match."

Aside from an exchange of breaks, the first set was dominated by the serve. Andreescu broke early and built a 3-0 lead before Sakkari pulled things level, breaking at 2-4 to get back on serve. Points were kept short as both women barreled toward an opening tiebreak, but Andreescu was able to keep the return pressure on the Sakkari serve. Andreescu faced just two break points in the opening set, but Sakkari faced five across four different service games. Sakkari saved four of them to keep Andreescu at bay.

After an electric 21-shot exchange won by Andreescu to open the tiebreak, Sakkari double-faulted to give the Canadian the mini-break at 2-0. That's all Andreescu needed, as she landed her first serve for the remainder of the tiebreak to take it 7-2 after 63 minutes. In a near-statistical dead-heat, Sakkari finished with 17 winners to 15 unforced errors, while Andreescu hit 16 winners to 16 unforced errors for the set.

"I think in the first set especially I was not going for my shots like I normally do," Sakkari said. "I was a little bit not very confident with my groundstrokes. I said, Maria, if you want to win this match, you have to go for it. It's better if you go for it and miss than just make balls, she hits winners.

"I didn't have the control of the match until middle of the second set. I felt like she was better than me, but then somehow I dug in and found a way to just turn things around. I was more brave after a certain point of the match, then got my energy level a little bit higher."

Though the rallies grew longer in the second set, Andreescu and Sakkari continued to batter the ball to head to yet another tiebreak. Andreescu remained more successful in pressuring Sakkari's serve, earning a break point at 4-4 and two break points in the 5-5 game. Each time, Sakkari stepped up to save them, getting the better of Andreescu in two nine-shot rallies and earning a return error on another.

Turning Point: Looking to win her first tiebreak in four tries against the World No.7, Sakkari dug in her heels. After exchanging a pair of early mini-breaks, Sakkari prevailed in a 20-shot exchange to earn a 3-1 lead and was the beneficiary of two forehand unforced errors to earn set points at 6-3. Andreescu leveled to 6-6 with a miraculous hook smash that kissed the sideline, much to Sakkari's disbelief, to come within two points of the win. But the Greek rebounded immediately to close out the 86-minute set, 8-6 in the tiebreak.

"I'm deadly honest, she was luckier than me in some parts of the match," Sakkari said, when asked about her reaction to the sideline winner at 5-6. "She had many net calls, line calls as well. But I just said you cannot lose the match because you're unlucky. Just try. I'm trying to be calm, not lose my mind. I want to live this experience, this tennis experience, until I'm done. I don't want to look back and say that I did not enjoy matches like today.

"I mean, there was a decent crowd staying until 2:30 at night. I said, Maria, you cannot give up. Just stay focused and stay calm and just make balls."

Andreescu broke Sakkari immediately in the final set to 2-0, but Sakkari responded immediately with a break at love in the next game. After holding serve to 3-2, Andreescu took an off-court medical timeout and returned with her upper left leg taped. On the resumption, Sakkari fired a service winner and three clean strikes off the ground to hold at 15 and level the decider at 3-3.

With Andreescu physically struggling, Sakkari played a disciplined return game to break to 4-3. With the break in hand, Sakkari closed out the match with a break, converting on her fourth match point to advance to her first US Open quarterfinal. 

Stat of the match: Sakkari saved 8 of 12 break points in the match and finished with 46 winners to 40 unforced errors. 

Sakkari on being brave: "It's something that I've been working with Tom since end of last year. But I felt like I lost that bravery after the French. I was more hesitant. I was not going for it so much. After my loss with Angie [in Cincinnati], I just practiced for two weeks. I had some very tough practices where I was crying because I could not feel my shots, I could not feel my tennis. But thankfully I had Tom and Yannis, my hitting partner, that supported me a lot.

"I lost my identity. That's how I called it. I lost myself, part of myself. With my psychologist, as well, I found a way to come back and feel again what I felt out there today. By telling myself to be more brave, it's not like, Maria, now be brave, and you're brave. It's just a process in practice and everything that has helped me to be more brave."

Andreescu on another physical match: "I was expecting that and I went out there with the right mindset, I think, and I did the best that I could. I wish I could have finished it in two sets, because I had my opportunities, but tennis is just like that sometimes.

"I take everything from this tournament and I just look at it, like, 'Wow, I really fought through that. That was crazy.' I was cramping from the start of the third set, and I just kept fighting, and for me that's all that matters. I did my best.

"At this point I really don't know [what the injury was], but I slid a couple of times, and I fell on my groin a little bit. I hope it's nothing too serious. But that affected me a little bit. I try not to think about it, but it's hard sometimes. I just need to take some days off and hopefully it'll be good."

Next up: Sakkari will face No.4 Karolina Pliskova for a spot in her second Slam semifinal of the season. The two have split their two previous matches, which both came on the clay in Rome.