WUHAN, China, Sept. 28 -- Hotly-contested sets that needed tiebreakers -- along with still more major upsets for the top seeds -- marked the quarterfinals of the ongoing Dongfeng Motors Wuhan Open here on Thursday.

Action on center court started with Australian Ashleigh Barty edging Czech 3rd seed Karolina Pliscova in a 4-6, 7-6 (3), 7-6 (2) nail-biter. It is Barty's first career victory over a player in the top five.

Both Barty and her Czech opponent put fantastic tennis on display, with Pliscova shooting 11 aces to 8 for the Australian. Barty displayed an impressive forehand with several beautiful drop shots leaving her opponent powerless to contest key points.

Barty came within striking distance of sealing the deal in the third set, with a game score of 40-0 at 5-4, but Pliscova clawed her way back up to deuce with some truly spectacular shooting.

She then grabbed another set point to level at 6-all and force a tiebreaker, during which it looked like it could go either way, until some stunning shots by Barty sealed the deal after a two and one-half hour slog.

Pliscova credited her opponent for playing smart tennis. "She was playing just little bit better today ... I think she was just more aggressive. In the end of the sets, she was just going for her shots," the Czech said.

Barty, who has had a breakout season on the tour this year, says she is feeling "more and more comfortable on the court. I'm playing with more freedom."

Barty goes on to meet 8th seed Jelena Ostapenko in the semifinals, who in the evening session recovered from a one-set deficit to stun world No. 1 Gabrine Muguruza 1-6, 6-3, 6-2 in just under two hours.

As she often does, Muguruza started off with command of the court out of the gate, going 2-0 before Ostapenko fought her to deuce in the third service game. But Muguruza's aggressive backhand was no match for the Latvian and she took the set with relative ease.

But it became clear that Ostapenko was finding her shooting rhythm in the second, storming to a 3-1 lead only to watch Muguruza level it at 3-all. But the Latvian was able to handle the pressure from Muguruza this time around and nabbed the set to force a decider.

"She started really well. I couldn't really get used to the rhythm. She was hitting pretty hard. Then in the second set I started to feel my game better and I started to play more aggressive," Ostapenko said of her turnaround performance.

The next match saw a poised Caroline Garcia of France move past Russia's Ekaterina Makarova in a tough match, 7-6 (3), 6-4.

Garcia was stronger on serve than she was on return throughout the match, and came out of the gate with a perfect service game, storming to a 4-0 lead before Makarova began to fight back, gradually leveling back to a tie but getting clobbered in the 7-3 breaker.

Garcia goes on to meet Greek qualifier Maria Sakkari in the semis, who vanquished Alize Cornet in yet another close match, 7-6 (2), 7-5.

The first set was an arduous 77 minute slog that saw several breathtaking rallies and stellar tennis from both sides, but it appeared at first as if Cornet would have the upper hand, as she broke her opponent's service game twice out of the gate.

But an unshaken Sakkari responded with two breaks of her own. The back and forth continued as the set progressed, making the tiebreak that eventually materialized seem inevitable after things leveled at 5-all.

In the second set, Cornet showed signs of anticipating her opponent' s swings, breaking Sakkari in the second service game. But the Greek fought back with a relentless all-court push that kept Cornet from getting any momentum out of her serves.

Sakkari said her mindset during the match was to "never stop fighting. Just run, take the opportunities, but mostly fight."

The ousters of Pliscova and Muguruza mean that the semifinals here in Wuhan will feature no top-seeded players.

WUHAN, China, Sept. 28 -- Hotly-contested sets that needed tiebreakers -- along with still more major upsets for the top seeds -- marked the quarterfinals of the ongoing Dongfeng Motors Wuhan Open here on Thursday.

Action on center court started with Australian Ashleigh Barty edging Czech 3rd seed Karolina Pliscova in a 4-6, 7-6 (3), 7-6 (2) nail-biter. It is Barty's first career victory over a player in the top five.

Both Barty and her Czech opponent put fantastic tennis on display, with Pliscova shooting 11 aces to 8 for the Australian. Barty displayed an impressive forehand with several beautiful drop shots leaving her opponent powerless to contest key points.

Barty came within striking distance of sealing the deal in the third set, with a game score of 40-0 at 5-4, but Pliscova clawed her way back up to deuce with some truly spectacular shooting.

She then grabbed another set point to level at 6-all and force a tiebreaker, during which it looked like it could go either way, until some stunning shots by Barty sealed the deal after a two and one-half hour slog.

Pliscova credited her opponent for playing smart tennis. "She was playing just little bit better today ... I think she was just more aggressive. In the end of the sets, she was just going for her shots," the Czech said.

Barty, who has had a breakout season on the tour this year, says she is feeling "more and more comfortable on the court. I'm playing with more freedom."

Barty goes on to meet 8th seed Jelena Ostapenko in the semifinals, who in the evening session recovered from a one-set deficit to stun world No. 1 Gabrine Muguruza 1-6, 6-3, 6-2 in just under two hours.

As she often does, Muguruza started off with command of the court out of the gate, going 2-0 before Ostapenko fought her to deuce in the third service game. But Muguruza's aggressive backhand was no match for the Latvian and she took the set with relative ease.

But it became clear that Ostapenko was finding her shooting rhythm in the second, storming to a 3-1 lead only to watch Muguruza level it at 3-all. But the Latvian was able to handle the pressure from Muguruza this time around and nabbed the set to force a decider.

"She started really well. I couldn't really get used to the rhythm. She was hitting pretty hard. Then in the second set I started to feel my game better and I started to play more aggressive," Ostapenko said of her turnaround performance.

The next match saw a poised Caroline Garcia of France move past Russia's Ekaterina Makarova in a tough match, 7-6 (3), 6-4.

Garcia was stronger on serve than she was on return throughout the match, and came out of the gate with a perfect service game, storming to a 4-0 lead before Makarova began to fight back, gradually leveling back to a tie but getting clobbered in the 7-3 breaker.

Garcia goes on to meet Greek qualifier Maria Sakkari in the semis, who vanquished Alize Cornet in yet another close match, 7-6 (2), 7-5.

The first set was an arduous 77 minute slog that saw several breathtaking rallies and stellar tennis from both sides, but it appeared at first as if Cornet would have the upper hand, as she broke her opponent's service game twice out of the gate.

But an unshaken Sakkari responded with two breaks of her own. The back and forth continued as the set progressed, making the tiebreak that eventually materialized seem inevitable after things leveled at 5-all.

In the second set, Cornet showed signs of anticipating her opponent' s swings, breaking Sakkari in the second service game. But the Greek fought back with a relentless all-court push that kept Cornet from getting any momentum out of her serves.

Sakkari said her mindset during the match was to "never stop fighting. Just run, take the opportunities, but mostly fight."

The ousters of Pliscova and Muguruza mean that the semifinals here in Wuhan will feature no top-seeded players.