Unseeded Serb Aleksandra Krunic is the first woman through to the Brisbane International 2018 quarter-finals after top seed Garbine Muguruza retired due to cramping with scores level at a set apiece.
Krunic had let slip a 4-2 lead in the opening set, only to lose it in a tie-break, and looked to be heading for the exit door when her Spanish opponent opened up a 5-2 lead in the second set.
The 53rd-ranked Serb rallied and eked out the second-set tie-break to force a decider and after dropping serve in the opening game of the third set, again found herself on the back foot.
With Muguruza a break up at 2-1 she collapsed on the baseline and retired injured soon after to hand Krunic a 5-7, 7-6(3), 1-2 ret. victory.
The top seed admitted she was unsure of her next move after pulling out of the Brisbane tournament – her only scheduled event before the year’s opening grand slam in Melbourne.
“Honestly, I have no idea yet,” the 24-year-old reigning Wimbledon champion said. “I didn’t expect to, you know, to not continue here.
“But I think I’m going to evaluate what options do I have now … maybe just go right away to Melbourne.”
Muguruza – the reigning WTA Player of the Year – had hoped to reclaim the world No.1 ranking she held for four weeks in 2017 by making the Brisbane final.
Muguruza said she felt her calves tightening early in the second set but dug deep to grab a break and lead 2-1 in the deciding third.
However, the Spaniard’s match was over after she fell to the ground in agony clutching her leg while attempting to make a backhand return.
Krunic will play the winner of Tuesday’s showdown between Sam Stosur’s first-round conqueror, seventh seed Anastasija Sevastova of Latvia, and Romania’s Sorana Cirstea.
“I’m happy that I’m past that kindergarten thinking that everything is terrible when I start losing,” Krunic said. “Because still, you know, I played against Garbiñe. It’s alright to lose a point against her.
” I literally tried to do everything I could and tried to outrun her and make her play longer points, because I couldn’t outhit her, definitely.
“So when she did her great shots, I just silently accepted it, said ‘good job’ inside of me, and was like, OK, well, let’s try to do something the next one.”
Meanwhile, world No.38 and last year’s Brisbane finalist Alize Cornet of France joined Krunic in the quarterfinals by downing Croatia’s Mirjana Lucic-Baroni 6-1, 7-5 on Tuesday.