Germany’s Alexander Zverev overcame some early frustration to fight back and beat American Marcos Giron in four sets on day one of the Australian Open.
The sixth seed destroyed a racquet after failing to serve out the second set to level, but took the tie-break and won 6-7 (8-10) 7-6 (7-5) 6-3 6-2.
French 10th seed Gael Monfils broke into tears after being on the receiving end of the biggest shock so far.
Monfils, 34, lost in five sets to 21-year-old Emi Ruusuvuori of Finland.
“I lost, I have zero confidence, I played badly,” said Monfils, a two-time Grand Slam semi-finalist.
“I know that I have lost a lot and it hurts me. I would like to wake up and tell myself that this nightmare is over, but I don’t know when it will stop.”
Austrian third seed Dominic Thiem, last year’s beaten finalist, started his bid to go a step better with a relatively straightforward win over Kazakhstan’s Mikhail Kukushkin.
US Open champion Thiem needed a tie-break to clinch the opening set before taking control to win 7-6 (7-2) 6-2 6-3.
Swiss 17th seed Stan Wawrinka, who won the title in 2014, made light work of Portugal’s Pedro Sousa, winning 6-3 6-2 6-4 in one hour and 36 minutes.
Canadian 14th seed Milos Raonic also raced through his opening match, beating Argentina’s Federico Coria in a 6-3 6-3 6-2 victory that was one minute faster than Wawrinka’s.