An error-strewn Novak Djokovic kickstarted his bid for an 11th Australian Open and unprecedented 25th Grand Slam crown in unconvincing fashion on Sunday, dropping a set to “incredible” teenage qualifier Dino Prizmic. On the other hand, women’s champion Aryna Sabalenka steamrolled her way into the second round with a 6-0, 6-1 win over Germany’s Ella Seidel.

Djokovic struggled to impose himself on the confident Croat on Rod Laver Arena before finally taming the 18-year-old 6-2, 6-7 (5-7), 6-3, 6-4 after a four-hour marathon. While far from his best, the World No. 1 showed no sign of the right wrist problem that hampered his build-up. “Well, I started off very well for a 36-year-old guy. But, geez, when you think about it, I’m double his age,” Djokovic said.