Four Score: For the first time in four tries, Madison Keys defeated good friend and fellow American Sloane Stephens, 7-6 (6), 4-6, 6-2, Friday afternoon in the quarterfinals of the Volvo Car Open in Charleston.

Stephens hadn’t just won all three of their previous meetings, she’d won them all in straight sets, including a 6-3, 6-0 demolition in the 2017 US Open final.

It appeared that the head-to-head dominance would continue as Stephens not only opened up a 4-2 lead, but served for the first set twice, at 5-4 and 6-5. And even though she failed to serve out the set a second time, Stephens won six points in a row from 4-0 down in the tie-break.

But Keys clawed back, winning the next four points, ripping a forehand winner to take the set. With a set finally under her belt, Keys played with a new energy against her compatriot-nemesis.

Stephens retaliated in the second set, making just five unforced errors to even the match at a set apiece, and she took a 2-1 lead in the third. But the No. 8-seeded Keys caught fire one last time, reeling off the last five games to oust the top seed after two hours and 12 grueling—but satisfying—minutes on Stadium court.

“It’s always hard playing Sloane because she’s truly one of my best friends on the tour, so that’s never easy,” Keys said in her on-court interview. “But obviously I’m very happy to get the win today and get through to the semifinals, and I’m glad to get some good matches under my belt, too.”

Stephens finished with 20 winners and 20 unforced errors in the match, while Keys was almost even, finishing with 34 winners to 35 unforced errors. But Keys was almost flawless in the third set, hitting just two unforced errors against six winners.

Keys was asked afterwards about her on-court coaching visit before the third set: “He was just telling me to keep going for my shots, move my feet a little bit faster," she said, "and just stay in the moment."

The moment wasn't too big for Keys this time, and she's now into her first semifinal since last year's US Open. She’s trying to reach her first WTA final since finishing runner-up to Stephens at the 2017 US Open.

“I feel like I’m trusting my game again now, and just knowing that even if I’m not playing perfect tennis, I can still win some good points and put together some good matches,” Keys said. “I’m excited to be in the semifinals and I’m looking forward to playing again tomorrow.”

Keys’ win over the No. 8-ranked Stephens was also her first Top 10 win of the year, and her best win in terms of ranking since she defeated a No. 4-ranked Angelique Kerber at Cincinnati last summer.