MADRID, Spain - No.8 seed Sloane Stephens is through to her first ever Mutua Madrid Open semifinal - and her first semifinal of the year - after powering past Petra Martic in two sets, 6-4, 6-3.

“I thought I played well,” Stephens told press afterward. “My opponent has been playing well, she won her first title in Istanbul, she's been playing real good, and I thought I served really well today.

“I made her play an extra few balls. And that was kind of the plan, so I thought I executed well and I'm happy to be through.”

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Stephens has had to dig deep in every match this week, being taken to three sets by Zheng Saisai in her previous match, having to battle past two-time Grand Slam winner Victoria Azarenka in the second round - edging to a 6-4,2-6,6-2 victory - and being pushed by Polona Hercog in her opener.  

The extra match play ultimately seemed to benefit her against Martic, the champion of Istanbul and the player who owns the most wins on clay in 2019, a 10-1 record.

The Croat stunned Garbine Muguruza in her opening match, but seemed to be favored by luck after that. She benefitted from a second-round walkover after Angelique Kerber withdrew with an ankle injury, and in the next round she was leading Donna Vekic  4-6,6-3,3-0 when she was forced to retire due to a hip injury.

Martic stayed toe-to-toe with French Open finalist Stephens for much of the opening set, but wasn’t able to break the American in the second as Stephens powered to a 6-4, 6-3 victory in an hour and 20 minutes.

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But after an impressive week in Madrid the Croat will still take away one big consolation prize: she’s guaranteed to make her Top 30 debut after the tournament.

Stephens fired 21 winners against Martic’s 12, and kept her unforced error count in check with 21 errors against Martic’s 24. She also posted some impressive numbers on serve: she won 76% of her first serve points, and as a result she didn’t give Martic too many opportunities - the Croat converted just one break point of two, while Stephens broke Martic three times in nine.

After a few games of feeling out each other’s level, Stephens capitalized on some vulnerable Martic second serves and teed off to earn the first break at 4-2 in the opening set. But Martic didn’t let that go unanswered, replying in kind the next game to get them back on serve.

She had a mammoth task on her hands in the very next game, as Stephens applied the pressure again and created four break chances - but Martic got herself out of trouble to keep them level at 4-4. She couldn’t pull off the same escape act, down 5-4 and serving to stay in it, and Stephens broke to take the opening set.

Martic saw a break chance come and go in the first game of the second set, Stephens’ forehand firing and forcing errors from the Croat. Martic would likely come to rue that missed opportunity - it was her only break chance of the set, and Stephens powered ahead to take the lead at 3-1. The lone break was all that Stephens needed, and she served strongly to keep Martic out of the contest as she powered her way to victory.

Into her first semifinal since last year’s WTA Finals in Singapore, Stephens awaits the winner between No.2 seed Petra Kvitova and Kiki Bertens - a rematch of last year’s Madrid Open final.

Read more: 'I believed my best years were ahead': Comeback queen Martic enjoys Istanbul triumph

“Petra has been playing great, she's had a great season,” Stephens acknowledged. “She's a great player. On clay, I have never played her on clay before. It will be a good match, very competitive.

“And Kiki, another great player. Her best surface is clay, so I think that will be a good match tonight, the rematch of the final last year.

“So, whoever I play, it will be really competitive but looking forward to it, obviously my first semifinal of the year, so like it is better late than never,” she added, laughing.