Former world number one Caroline Wozniacki suffered her first ever Australian Open first-round exit with a surprise loss to Yulia Putintseva.
Wozniacki, a semi-finalist at Melbourne Park in 2011, went down to the Kazakh 1-6 7-6 (7-3) 6-4 on Hisense Arena on Monday.
The Danish 16th seed had never been sent packing in the opening round in Melbourne before, but she did make a second-round exit last year.
It had appeared unlikely after a dominant first set that ended in 31 minutes, with Putintseva's 17 unforced errors decisive.
But Putintseva, 21, took out her win in three hours, 12 minutes, with Wozniacki sending a forehand into the net on match point.
Wozniacki had needed a medical timeout for treatment on a foot injury, while Putintseva also appeared to be struggling physically in the Melbourne heat.
Putintseva twice fell behind a break in the second set before her fightback, with a break in the ninth game of the third crucial.
Sara Errani, Sloane Stephens, Anastasia Pavlyuchenkova and Anna Karolina Schmiedlova were among the other women's seeds to exit on the opening day.