No.4 seed Elena Rybakina has withdrawn ahead of the Dubai Duty Free Tennis Championships quarterfinals due to gastrointestinal illness. As a result, the unseeded Jasmine Paolini advances to the semifinals via walkover.

No.26-ranked Paolini will face another unseeded player in Sorana Cirstea, who pulled off a remarkable comeback from a set and 5-1 down to upset No.7 seed Marketa Vondrousova 2-6, 7-6(1), 6-2 in 2 hours and 41 minutes. Cirstea saved six match points en route to notching her 21st career Top 10 win, and second of 2024.

The winner of the semifinal between Paolini and No.22-ranked Cirstea will make her Top 20 debut in next week's edition of the WTA rankings.

Rybakina has been one of the form players of 2024, winning two titles in Brisbane and Abu Dhabi and compiling a 17-3 record overall. The Kazakhstani's Middle East swing has been particularly strong; she backed it up with a run to the Doha final last week, then notched two further wins in Dubai.

After battling for 2 hours and 39 minutes to get past qualifier Magdalena Frech 7-6(5), 3-6, 6-4 in the third round, Rybakina had admitted to feeling the effects of a strenuous month.

"I'm happy that I'm still winning the matches," she said. "But I can see by the level that of course physically and everything it's dropping a bit. I don't know how much I can push and how much I can recover in this half day."

No.26-ranked Paolini will make her debut in the semifinals of a WTA 1000 event. The Italian, who received a nomination in the 2023 WTA Awards for Most Improved Player, also reached the fourth round of a major for the first time at the Australian Open last month.

How Cirstea pulled off her comeback: Though the first set was tighter than the scoreline suggests, Vondrousova was firmly in control of the most important points. The Wimbledon champion saved all seven break points against her in the opener, repeatedly outfoxed Cirstea with the drop shot-lob combination and sustained her momentum to reach 5-1 in the second set.

But with her back to the wall, Cirstea began swinging freely. At 5-1 down, the 33-year-old saved the first two match points against her with a pair of aces. In the next game, a winner on the drive volley -- a shot that would be key to the turnaround -- staved off a third. Down 5-3, Cirstea fended off a fourth and fifth on serve.

At 5-5, Vondrousova snapped the Romanian's run of four straight games, and served for the match for a third time. But despite some desperate defense, she could not convert a sixth match point as Cirstea found a backhand winner.

Photos: All of 2024's wins from match point down

Having paid the price for lapsing into passivity in the second set, Vondrousova was unable to regain the upper hand in the tiebreak or the decider as Cirstea powered to the finishing line.

"This has to be the biggest comeback of my career," Cirstea said in her on-court interview. "To be honest, at a set and 5-1, I wasn't thinking about winning any more. I was like, at least make it nice for the public, at least make it longer and give them a bit nicer tennis. I still don't know how I managed it."

Cirstea advances to her third career WTA 1000 semifinal following Toronto 2013 and Miami 2023.

Cirstea saves six match points vs. Vondrousova to make Dubai semis