"I felt in trouble in the second set when I was 2-0 up," Muguruza said. "I started to feel my calves were cramping." Muguruza had won a tight first set and appeared heading for a straight sets win over Krunic when she opened up a 5-2 lead in the second. However, she began to struggle in the 30 Celsius (86 Fahrenheit) heat and oppressive humidity as Krunic fought back to win the second set on a tiebreak.
Wimbledon champion Garbine Muguruza has been forced to withdraw from the Brisbane International.— BBC Sport (@BBCSport) January 2, 2018
She collapsed following a serve and had to be helped from the court.https://t.co/Ib4qjnbm3D pic.twitter.com/KdX433yw7h
Muguruza received treatment from the physio on court before the start of the decider and broke Krunic only to collapse while serving to consolidate the service break. "I continued to think that with the match they (cramps) might go away, and then they were increasing, increasing. And then I had a lot of my body cramping," Muguruza said. The loss ends any hope Muguruza had of leapfrogging Simona Halep and becoming world number one before the seedings are decided for the Australian Open, which begins on January 15.
"I start to feel my calves were cramping. And I continued to think they might go away, and then they were increasing, increasing"— #BrisbaneTennis (@BrisbaneTennis) January 2, 2018
- Garbiñe Muguruza on her mid-match retirement #BrisbaneTENnis pic.twitter.com/tZkTTd2c70
"I'm very disappointed to be withdrawing from the Brisbane International," he added. "I came here with every intention of making a strong start to the year, but sadly my team and I don't feel that I'm where I need to be just yet to compete at the highest level." Earlier, 21-year-old South Korean Chung Hyeon stunned fifth seed Gilles Muller from Luxembourg 6-3, 7-6 (7/1), while US qualifier Michael Mmoh upset Argentine Federico Delbonis 6-3, 6-4. Britain's Kyle Edmund survived a barrage of 18 aces from 18-year-old Canadian Denis Shapovalov to win in three sets 6-7 (5/7), 7-6 (7/4), 6-4, and Uzbekistan's Denis Istomin downed seventh-seeded Bosnian Damir Dzumbhur 6-7 (4/7), 6-3, 6-2.
Andy Murray has unfortunately had to withdraw from the Brisbane International due to a right hip complaint pic.twitter.com/trjo0Vovym— #BrisbaneTennis (@BrisbaneTennis) January 2, 2018