Belinda Bencic is through to the third round after grinding out a 7-5, 7-5 win against Jelena Ostapenko on Thursday.
The No. 6 seed took the first set having broken Ostapenko's serve four times in a frantic opening to the contest on Margaret Court Arena with momentum swinging both ways.
Bencic, who reached the US Open semi-finals last year, responded well to going a break down in the second set by the hard-hitting Latvian.
The 22-year-old Swiss regained her composure and responded with two breaks at 5-4 down to overcome the 2017 French Open winner for the first time in her career, slamming down an ace to sealed her place in the next round.