Novak Djokovic won in straight sets against the hecklers, too. Djokovic responded to an Australian Open fan who yelled an angry message to him after the Serbian rolled to a 6-1, 6-4, 6-4 victory over 26th-seed Tomáš Macháč.

With this victory, Djokovic continues his quest for an 11th Australian Open title and a record-extending 25th Grand Slam. He now prepares to face another Czech opponent, Jiří Lehečka, who advanced with a 6-2, 6-3, 6-3 win over Benjamin Bonzi.

Novak Djokovic sought assistance from a trainer for some trouble breathing Friday night, and went back-and-forth with one particularly loud spectator, but when the ball was in play at the Australian Open against Tomas Machac,