NEW YORK, NY - AUGUST 30: Bernard Tomic of Australia returns a shot to Damir Dzumhur of Bosnia and Herzegovina during her first round Women's Singles match on Day Two of the 2016 US Open at the USTA Billie Jean King National Tennis Center on August 30, 2016 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Andy Lyons/Getty Images)

Australian Bernard Tomic has been knocked out of the US Open in the opening round by little know world No.72, Damir Dzumhur.

Tomic went down in four sets, 6-4, 6-3, 4-6, 7-6 (7-0).

The 17th seed's shock loss was compounded by yet another controversy.

After being annoyed at something said by a member of the crowd during the opening set, Tomic responded to the fan, which was heard on television microphones.

“Suck my balls,” Tomic was heard to say prior to his opponent's serve.

“I will put my balls in your mouth.”

Tomic continued after Dzumhur faulted, adding, “I will give you some money to make you feel good”.

No action was taken against the 23-year-old at the time, however, he may still face sanction in the coming days.