World No.1 Ashleigh Barty made her Porsche Tennis Grand Prix debut a successful one, ousting 2017 champion Laura Siegemund 6-0, 7-5 to reach the quarterfinals in Stuttgart.

Top seed Barty fended off a second-set surge by homeland heroine Siegemund to collect an 84-minute victory and book a meeting in the elite eight with either No.6 seed Karolina Pliskova or Jelena Ostapenko, who will face off on Thursday.

"I felt like I had to really find some good stuff tonight, and even though at times it was a little bit scrappy, I felt like it’s going to be on my terms for a lot of that match," Barty told the press, after her win.

"As for getting my feet wet the first match, anyone you play you have to find a way, you have to be prepared to work and be prepared to tactically find your way around the court," Barty continued. "So whoever the first match was going to be, it was always going to be a perfect one in my eyes to get myself into the tournament to enjoy it."

Barty was sheer perfection behind her first service, winning all 24 of the points where she got her first serve into play. She backed that outrageous stat up with 19 winners, compared to 13 winners from World No.58 Siegemund.

Barty had won the previous meeting between the pair, at 2020 Doha, in straight sets, and she picked off right where she left off by carving out winners from all sectors of the court to race through a bagel opening set. Barty never faced a break point in the first set, while the 11 unforced errors by Siegemund in the opening frame sealed her fate.

In the second set, though, Siegemund showed off the form which brought her to two straight finals in Stuttgart, with a runner-up showing in 2016 preceding her 2017 title run. The crafty German deployed a drop-volley winner to eke ahead by a break early in the set at 2-1.

World No.1 Barty bounces former champ Siegemund in Stuttgart: Highlights

2021 Stuttgart

But Barty matched Siegemund in creative shots, and after a double fault by Siegemund to give the Australian a break point, Barty fired a winning lob to break back for 2-2.

As the lobs piled up, flying off the racquets of both players with regularity, Siegemund did well to fend off four break points during a hold for 3-3. Barty had to serve her way out of trouble en route to a hold for 4-4, but eventually the Aussie took charge, and at last earned the critical break in the final game of the match to close out a tough second set and the resulting victory.

Photo by WTA/Jimmie48

Defending champion Petra Kvitova joined Barty in the quarterfinals, but not without a struggle, as the No.7 seed had to outlast Maria Sakkari 6-3, 3-6, 6-3 after nearly two-and-a-half hours of closely-contested action.

"I think it was a few factors today I should be proud of," Kvitova said, during her post-match press conference. "Definitely, one of them is that I stayed there until the end, that I still was fighting even in those games which I didn’t win, even on my service game, even in the second set which I lost. But I think that’s how the effort was, that I was still there, fighting for every point."

Defending champ Kvitova outlasts Sakkari in Stuttgart clash: Highlights

2021 Stuttgart

Kvitova continued her path through a difficult draw as her first two matches have been against Top 20 opposition who happened to fall just outside the seedings in this loaded field. Unlike her straight-set victory over Jennifer Brady in the first round, World No.19 Sakkari pushed Kvitova to the limit before the Czech collected the final three games to claim the win.

10th-ranked Kvitova has now won her last six matches at the Porsche Tennis Grand Prix, and improved to 4-1 against Top 20 players in 2021. Kvitova saved 13 of the 16 break points she faced in the battle, while Sakkari was nearly as impressive in that regard, erasing nine of the 13 break points against her.

Kvitova needed just a single break of serve in the opening frame, which came at 2-1, as she eased to the one-set lead, staving off the three break points she faced in the process. Kvitova fired nine winners in the first set, while Sakkari could only muster up two winners during that timeframe.

The Greek turned the tables by going up an early break in the second set, and though Sakkari allowed Kvitova back on serve at 4-3, the unseeded player moved back ahead by breaking for 5-3 after a grueling tussle where she converted her eighth break point of the game with a dropshot winner. A routine hold in the following game let Sakkari tie up the clash.

The decider started with Kvitova ahead after breaking for 3-1 with a backhand crosscourt winner, but Sakkari struck right back to pull back on serve. Another titanic game followed at 4-3, which Kvitova at last took on her fourth break point after an ill-timed double fault by the Greek, and Kvitova ultimately found more fiery winners down the stretch to power her way into the last eight.

Photo by WTA/Jimmie48

Earlier on Wednesday, Anett Kontaveit continued to rack up wins in Stuttgart, as she notched a 7-5, 6-4 upset of No.3 seed Sofia Kenin and became the first player into the 2021 Porsche Tennis Grand Prix quarterfinals.

"It was a very close match and I’m very happy to be through," Kontaveit said, in her post-match press conference. "I felt like the first set was a little bit on and off. I feel like I served really well throughout the match and that’s definitely what helped me."

World No.27 Kontaveit has emerged as a Stuttgart specialist over the past few editions of the indoor clay event. She has now reached the quarterfinals or better in all four of her main-draw tournament appearances, including a runner-up showing at the most recent edition in 2019.

The Estonian has now improved to 11-3 at the event with her 94-minute victory over last year’s Australian Open champion Kenin, in the first meeting between the combatants.

Kontaveit’s win over World No.4 Kenin is the twelfth Top 10 win of her career, and her first of the season. Notably, Kontaveit’s first-ever Top 10 win came at the Porsche Tennis Grand Prix in 2017, where she defeated then-World No.6 Garbiñe Muguruza en route to the quarterfinals.

Kontaveit used aggressive play to take the victory, with 31 winners to just 20 unforced errors. By contrast, Kenin's 29 unforced errors outweighed her 19 winners, as the American suffered a third straight defeat. 

Kontaveit never faced a break point in the first set, but Kenin stayed with the Estonian nearly the whole way through by fending off nine break points in total up to 6-5. At last, though, Kontaveit took her chance, converting her tenth break point of the opening frame when it counted most: on set point, after a Kenin backhand miscue went wide.

In the opening game of the second set, Kenin tightened up that backhand side to earn her first break of the day with a winner off of that wing, and eventually edged ahead 2-0. But the errors continued to mount from the American and Kontaveit took control, breaking Kenin twice in a row and reeling off five straight games to lead 5-2.

Sturdy returning by Kenin helped her save a match point at 5-3 and the American did earn one break back. However, at 5-4, Kontaveit twice chased down dropshots by the No.3 seed for passing winners, and the 2019 runner-up finally converted her third match point after one last long forehand by Kenin.