No.12 seed Ons Jabeur overcame two losing streaks to reach the Volvo Car Open semifinals with a 6-3, 6-3 defeat of No.14 seed Coco Gauff in 1 hour and 20 minutes.

Last year the Tunisian put together a breakthrough season, compiling a 27-11 record and rising to the edge of the Top 30. But during 2020, Jabeur also went 0-5 in quarterfinal matches and 0-2 against Gauff, losing to the American teenager 4-6, 6-4, 6-1 in Lexington and 6-4, 6-3 in Rome.

"Maybe this year is a revenge year for me," Jabeur said. "Honestly, mentally-wise I'm much better. I'm getting there. I had my opportunities against her last year. She's a great player. I know exactly what I'm going to face and I was ready for the battle."

On the green clay of Charleston, Jabeur turned both records around in style. After a scrappy opening set which saw six breaks of serve, Jabeur peaked in the fifth game of the second set, coming through a crucial hold with a shotmaking clinic. That would give her enough momentum to get over the finishing line, notwithstanding a late fightback from Gauff in which the 17-year-old saved two match points on her own serve.

Ons Jabeur's career WTA semifinals
2018 Moscow 500, finalist
2019 Eastbourne 500, semifinalist
2019 Tianjin 250, semifinalist
2021 Charleston 500, semifinalist or better

2021 Charleston 500 Highlights: Jabeur masters Gauff challenge to reach SF

"I'm glad that I'm playing good now. I know that clay is amazing and I gotta say, I have been enjoying sliding a lot lately. It's the best part of the clay. I like the green clay. It's different than the red clay but I like it. The bounce is not too high, it's not too low. It's a good balance for me.

"I'm just trying to play my game. I'm trying to enjoy after a very tough start to the season. A lot of expectations. I'm really glad I got to prove myself this week and I'm in the semifinals."

Gauff, who took a medical timeout down a break at the first changeover of the match, was particularly beset by 13 double faults and, in the first set, a meager 38% first-serve percentage. She served at least one double fault in all but two of her service games, and finished the match with a total of 31 unforced errors to 15 winners.

Jabeur will next face the unseeded Danka Kovinic, who came back from the brink to beat Yulia Putintseva 6-7(2), 7-5, 6-1 in two hours and 52 minutes. The Montenegrin was a game away from defeat serving at 4-5 in the second set, but hit her stride just in time to reel off nine of the last 10 games and reach her maiden WTA 500 semifinal.

"To be honest I don't know the real secret why I'm playing well here," Kovinic said. "I just think the surface suits me well. It's a little bit faster than the red clay. I just think my game, and my kick-serve is pretty tricky for my opponents to return. I just feel really good here."

Danka Kovinic's career WTA semifinals
2015 Tianjin 250, finalist
2016 Istanbul 250, finalist
2016 Tianjin 250, semifinalist
2021 Charleston 500, semifinalist or better

Neither player was able to seize momentum through a nervy opening set, but buckling down for a tactic of gritty consistency paid off for Putintseva at its business end. Kovinic's power hitting was suffering from inconsistency - at one point, the World No.91 pulled off a mid-rally tweener, only to botch the ensuing putaway.

But at the end of the second set, Kovinic loosened up and let rip. A series of winners forced a decider, which she dominated as an increasingly frustrated Putintseva lapsed into uncharacteristic error.

"How the match started, I thought it's never going to end," said Kovinic. "I stayed composed through the whole match - I didn't show too many emotions, which sometimes I do on court, and I think that was the main improvement in my game."