WUHAN, China - Wildcard Elena Rybakina has booked her first-ever Premier 5 quarterfinal berth after an ailing Simona Halep was forced to retire in the first set of their Dongfeng Motor Wuhan Open clash. 

Formerly the No.3-ranked junior in the world, Rybakina rocketed into the WTA’s Top 50 after claiming the first WTA title of her career in Bucharest and reaching the final in Nanchang earlier this month.

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In Wuhan, Rybakina made good on her wildcard when she scored a dramatic, three-set victory over Chinese qualifier Zhu Lin, 7-5,2-6,6-0. She had to weather another battle in the second round against lucky loser Ons Jabeur, needing just under two hours to win 6-1, 6-7(3), 6-2 and book her clash with the former World No.1 Halep.

The 20-year-old Kazakh did well to stay apace during the opening nine games of their match. After dropping serve early on, she broke Halep to love to keep them on serve at 2-2. 

"I started a little bit nervous," Rybakina admitted afterwards. "But I played good the last few games. I went on court with nothing to lose, to show my best game, to fight."

Rybakina then had to turn around a 4-2 deficit as Halep threatened to run away with the score, and she rattled off three games in a row. She kept the pressure firmly on Halep as she broke again at 4-4 to serve for the set. 

But that’s when a struggling Halep called for a medical time out and, after attempting a few points upon resumption, was forced to retire from the clash citing a low back injury, trailing 5-4, (ret).

“It’s a lower back [injury],” Halep told journalists afterward. “I think it’s more muscle, but I don’t know yet because I didn’t check it properly. [At] 4-all, 0-30, with the backhand. I had a sharp pain.

“I don’t know yet [if it’s the same as the previous injury]. It looks a little bit different but it’s still the same zone.”

Despite the surely bittersweet ending to the match, the victory marks yet another milestone for Rybakina in her breakthrough season: her biggest win-by-ranking to date over No.6 Halep, and her second career WTA Top 10 win.

"Of course, I didn't want to win the match like this," said Rybakina. "The worst thing that can happen to an athlete is injuries - I wish Simona a speedy recovery and I'm just happy to be in the quarters." The youngster could still take a moment to appreciate her meteoric rise in 2019, though. "It's amazing," she recalled. "I started the year [around] World No.200 - the goal for the year was Top 100, then it was Top 50, and it's getting better and better."

In photos: High five: The previous winners in Wuhan from Kvitova and Sabalenka

Up next for Rybakina, she’ll await the winner between No.9 seed Aryna Sabalenka vs No.6 seed Kiki Bertens for a spot in her first Premier-level semifinal.