MELBOURNE, Australia - 2016 champion Angelique Kerber pulled off an improbable comeback against an on-fire Hsieh Su-Wei in two hours and eight minutes, 4-6, 7-5, 6-2 to reach her second Australian Open quarterfinal in three years.
Hsieh, a former doubles No.1, was last in the fourth round of a Grand Slam a decade ago at this very tournament, and made it through the likes of reigning Wimbledon champion Garbiñe Muguruza and Agnieszka Radwanska to book the clash against Kerber, who has yet to lose a match this season after going undefeated in Hopman Cup and winning the Apia International Sydney.
"I think the key at the end was that I really could run forever," the German said, indicating how much she was stretched. "I felt that from the first point until the last."
Recovering from an early break to start the match, the 30-year-old Hsieh used all of her guile to capture six of the next seven games, taking the opening set and later finding herself three points from victory in the tenth game of the second set.
"The first two games were not easy for me, because I was thinking, 'Oh, that's Kerber,' Hsieh said after the match. "And I make a lot of mistakes on the first two games. Then the third game I try to do my plan again, to forget opponent and try to do my shot, and then I come back a little bit and it was going well after that.
"She was serving pretty well, and of course then it gave me some pressure when I leading 5-4. I was thinking, 'Oh, I have a chance. I want to hang in there and then get my shot.' Before that she was making some errors, she was winning easy on her serve. I know it's not going to be easy. I was thinking we gonna go into 5-5, or a tiebreak."
With a win over five-time major champion Maria Sharapova, Kerber has shaken off a rough 2017 to play some of her best tennis in over a year, spending the off-season with famed coach Wim Fissette - formerly with Simona Halep, Kim Clijsters, and Johanna Konta - and dug deep to level the match.
"I'm happy that I won the second set and then I could play my tennis again in the third set," she admitted.
"I was just trying to play point by point and not think about how well she played in the previous hour. I was trying not to think about the scoring. I think the fight was very important for me today."
The German relied on her superior physicality to race out to a 5-1 lead in the decider, and while Hsieh had some magic left, the former WTA World No.1 clinched the victory on her third match point.
The combatants were met with a standing ovation after the high-quality encounter, which yielded a combined 73 winners and an array of breathtaking rallies.
"It's always good to come back after 10 years and you make fourth round again," Hsieh said. "With this age, I thinking if I try to work a little bit harder maybe I can -- I hope I can have more success."
Kerber, though, has the last eight to look forward to.
"Of course it gives me a lot of confident to know that I can turn around matches, that I can come back and win matches like this because the game style was really tricky," she said.
"It's great to be back in the quarterfinals again. I had a tough offseason and now I just want to enjoy it. It's great -- I know I played well."
Standing between her and a return to the semifinals is longtime rival Madison Keys, who put on a triumphant display to defeat No.8 seed Caroline Garcia to start the day. The pair last played at the 2016 BNP Paribas WTA Finals Singapore presented by SC Global, but Kerber and Keys have put on some enthralling performances in the past, most notably their 2014 Aegon International final (won by Keys) and their 2015 Volvo Car Open final (won by Kerber).