Ashleigh Barty is in line to break into the world's top 10 for the first time after trumping seventh seed Kiki Bertens to reach the Miami Open quarter-finals.
The Australian No.1 dug deep to prevail 4-6 6-3 6-2 in one hour and 53 minutes on Tuesday to continue her milestone season.
A first-time grand slam quarter-finalist at the Australian Open and runner-up in Sydney, Barty will leapfrog Serena Williams in next week's rankings and looks all but assured of joining Samantha Stosur as only the second Australian in the past decade to crack the world's top 10.
Only a quarter-final loss to Czech nemesis Petra Kvitova and a surprise title triumph from Chinese No.1 Wang Qiang can deny Barty.
But the 22-year-old's fate is in her own hands and she can seal her place among the elite with a breakthrough first win in five meetings with Kvitova, the Australian Open runner-up and world No.2.
"Absolutely not," Barty said when asked whether she was tired of facing Kvitova.
"It's always an exceptional challenge. She's one of the best in the world. I look forward to it."
Unlike her none-from-four struggles against left-handed Kvitova, Barty now holds a 4-0 record over Bertens.
The Queenslander paid tribute to her new performance coach Ben Crowe after progressing to the last eight of a WTA Premier Mandatory event, one of the four biggest tournaments outside of the grand slams and the season-ending WTA Finals.
"He's made an astronomical difference," she said.
"We've created a really tightly knit group: we trust each other, we bounce ideas off each other and ultimately we try to get the best out of each other."
Kvitova has her own motivations in Miami.
The 29-year-old dual Wimbledon champion can claim the top ranking for the first time if she lifts the title.
"I'm glad I was able to finish the match," Kvitova said after overcoming a rain delay of more than two hours to oust Caroline Garcia 6-3 6-3, having led 5-2 in the second set before the stoppage.
Kvitova has already defeated Barty twice this year, in a third-set tiebreak in the Sydney decider and 6-1 6-4 in the quarters at Melbourne Park.
Anett Kontaveit will face Su-Wei Hsieh in the other quarter-final from the top half of the draw after Indian Wells champion Bianca Andreescu, struggling with a right shoulder problem, retired while trailing Kontaveit 6-1 2-0.
Hsieh overcame former world No.1 Caroline Wozniacki 6-3 7-6 (7-0) 6-2.
World No.3 Simona Halep booked a last-eight meeting with Wang - a 7-5 6-4 winner over compatriot Wang Yafan - with a 6-3 6-3 defeat of three-time Miami Open champion Venus Williams.
Fifth seed Karolina Pliskova faces fellow Czech Marketa Vondrousova in the last quarter-final.
Australian Associated Press
