No.7 seed Coco Gauff won the first tour-level grass-court quarterfinal of her career, knocking out No.4 seed Karolina Pliskova 7-5, 6-4 in 1 hour and 37 minutes at the bett1open on Friday.

Gauff of the United States had lost her only prior meeting against last year's Wimbledon runner-up Pliskova, and she had also lost her last four matches against players ranked inside the Top 10.

But that all changed on Friday as World No.13 Gauff, who recently reached her first Grand Slam singles final at Roland Garros, fought off four set points in the first set en route to victory over seventh-ranked Pliskova.

Words from the winner: "I’m super happy with how I played today," Gauff said afterward. "Playing her on grass, with her serve, how flat she hits the ball, it was really tough to be honest. I had to come up with a couple different game styles that I normally don’t use, but sometimes it’s like that.

"A first semifinal on grass is pretty cool, and also I feel like the opponents I’ve played this week haven’t been easy, especially today, so I’m proud of myself about that."

Match moments: At 5-4 in the opener, Pliskova hit a stunning forehand winner down the line to garner two set points. But Gauff used excellent serves and deft slices to ward off those two as well as two more, before holding for 5-5 after a 15-minute game.

Gauff’s determination paid off immediately, as she broke Pliskova in the very next game with a backhand winner down the line. Gauff kept the momentum at 6-5, serving out the set at love.

Czech Pliskova, who was playing her first match against a Top 20 player this season, started the second set with a 2-0 lead, but Gauff quickly pulled back on serve with a passing winner.

Another lengthy game at 4-4 went Gauff's way, as she converted her fourth break point and grabbed a chance to serve out the win. The 18-year-old American took that opportunity, slamming her fifth ace of the day to polish off the match.

Jabeur battles past Sasnovich

Gauff's semifinal opponent will be No.1 seed Ons Jabeur, who came back from a set and a break down to earn a 6-7(3), 6-2, 6-2 win over Aliaksandra Sasnovich in a nearly 2-hour quarterfinal.

World No.38 Sasnovich has now pushed Jabeur to three sets in each of their three meetings, but Jabeur has come out on top in all of those encounters.

Jabeur, currently at a career-high ranking of World No.4, has won 28 matches so far this season, more than any player other than World No.1 Iga Swiatek.

Watch this: Jabeur hits two perfect tweeners en route to Berlin semis

On Friday, Jabeur out-winnered Sasnovich by 19 to 15, and she had six fewer unforced errors than Sasnovich.

Sasnovich pulled off a comeback from 5-2 down in the first set, eventually reeling off the final four points of the tiebreak to squeak out the one-set lead. Sasnovich broke Jabeur in the first game of the second set as well.

But Jabeur turned the match around from there, finding deep, powerful returns to pick up six of the next seven games and claim the second set. Jabeur cracked the third set open with a break for 4-2 and held on from there, hitting a tweener for good measure in the last game.

Head-to-head: Gauff has won three of her four meetings with Jabeur, but this will be their first clash on grass. In their most recent match, Gauff ousted Jabeur in the Round of 16 at 2021 Roland Garros.