Two-time US Open finalist Victoria Azarenka criticised umpire Aurelie Tourte during her first-round match at Flushing Meadows on Tuesday.
The 26-year-old eased through a 6-1 6-2 victory over Lucie Hradecka, but she had a run-in with the umpire between points.
Azarenka asked Tourte if she had ever played tennis before, to which the official replied, "yes", and the Belarusian sniped: "You did? You probably weren't very good."
Azarenka will face Yanina Wickmayer in the next round.