No.1 seed Ashleigh Barty came back from the brink to reach her third semifinal of 2021 at the Porsche Tennis Grand Prix, winning the last four games to defeat No.6 seed Karolina Pliskova 2-6, 6-1, 7-5.

In Barty's first tournament on red clay since winning Roland Garros 2019, the Australian was two points from defeat five times as Pliskova served for the match at 5-4 in the decider. However, she pulled off a superb recovery to cap a contest that had been full of tactical twists and turns, improving her record against Pliskova to 5-2.

"In a sense it was probably a match of two sets," said Barty afterwards. "In the first set I wasn't able to build any pressure. Kaja was getting in and out of her serving games too quickly, and in turn was then having freedom on my service games. But being able to flip that switch right from the first game of the second set was important. To then make it more of a physical match was what we were after, and over time we were able to get the match back on my terms as much as we expected."

The result also extends Barty's winning streak against Top 10 opposition to eight. This record dates back to the 2019 Shiseido WTA Finals Shenzhen, where she lost 3-6, 6-3, 6-4 to Kiki Bertens in her second round-robin match before bouncing back to win the tournament.

"I try and narrow that focus for every single match regardless of who I'm playing," said Barty. "But when you come up against Top 10 opponents, you have to go to that level above to be able to compete. They force you to bring your best. With a lot of the girls in the Top 10, we've had plenty of matches that have gone either way, different experiences, so each time I love that challenge of testing myself against the best."

Ashleigh Barty's last 10 matches vs. Top 10 players
d. Belinda Bencic 5-7, 6-1, 6-2, RR WTA Finals 2019
l. Kiki Bertens 3-6, 6-3, 6-4, RR WTA Finals 2019
d. Petra Kvitova 6-4, 6-2, RR WTA Finals 2019
d. Karolina Pliskova 4-6, 6-2, 6-3, SF WTA Finals 2019
d. Elina Svitolina 6-4, 6-3, F WTA Finals 2019
d. Petra Kvitova 7-6(6), 6-2, QF Australian Open 2020
d. Aryna Sabalenka 6-4, 6-7(5), 6-3, QF Miami 2021
d. Elina Svitolina 6-3, 6-3, SF Miami 2021
d. Bianca Andreescu 6-3, 4-0 ret., F Miami 2021
d. Karolina Pliskova 2-6, 6-1, 7-5, QF Stuttgart 2021

Pliskova's uptick in form in Stuttgart has been noteworthy. The Czech had spoken about her satisfaction in raising her level between her first- and second-round wins, and she started off strongly against Barty in a set decided by play on big points. Pliskova captured both of the break points she brought up with booming off forehands, while Barty was unable to convert any of her three chances.

Canny tactical adjustments flipped the second set towards the World No.1. Bringing Pliskova to net with short slices worked well as it opened, with Barty setting herself up perfectly for passing shots. Her signature slice, knifing from line to line, was also utilised superbly in capturing the double break for 4-1 after a four-deuce tussle.

"I try to use it differently depending on what surface we're on," Barty said about her trademark shot. "At times I want to use it with a little more aggression and at other times I want to use it to change the tempo of the match completely. It's about finding that balance. But it changes with each match and each opponent, not just the surface."

But a careless lapse as the decider got under way seemed as though it would cost Barty the match. She threw in a pair of double faults to go down 1-2, and was repeatedly frustrated in her attempts to get back on serve.

Indeed, Pliskova was the better player on big points for the majority of the match, converting all three break points on the Barty serve and saving 14 out of the 19 she faced, including the first eight of the deciding set. The former World No.1's first serve, which garnered her eight aces, came to her rescue time and again as she went up 5-3.

But serving for the match, Pliskova's form began to oscillate. Though she fended off four break points with unreturned serves, cheap errors - in part elicited by dogged Barty counterpunching - prevented Pliskova from reaching match point. Facing a fifth break point, she found the net with a forehand.

The missed break point chances throughout the set had aided in her in that game, Barty said: "I had plenty of opportunities in that third set on Kaja's service games, so I just wanted to press again and really make her earn that last game."

Having levelled the score, Barty took control, racing through 10 of the last 12 points to set up a semifinal clash against either No.4 seed Elina Svitolina or No.7 seed Petra Kvitova.

Barty comes back from brink against Pliskova to reach Stuttgart SFs: Highlights