"Shut up." This was what Australian Open champ, Stan Wawrinka, suddenly uttered to a spectator at Flushing Meadows during a tight U.S. Open second-round game which he won against Brazil's Tomaz Belluci on Wednesday.

Wawrinka was already in a two-set lead against his opponent when he committed some unexpected errors that prompted him to even tell himself: ''Too many mistakes!''

The fourth set, according to AP Sports, was equally challenging as a fan who was obviously drunk was repeatedly bothering him. The player turned to the rowdy person in the crowd and shouted ''Shut up, man! Seriously, shut up.'' He later on won the match and claimed a 6-3, 6-4, 3-6, 7-6 (1) against Belucci.

''At the end of the day, they start to get a little bit drunk. It was OK. I had to talk to a few of them. At the end, it's normal. ... Everybody was into the match. That's OK. It can happen,'' he explained during a news conference after the match.

He also said in the AP Sports article that he felt comfortable while playing and that he was "serving big."

"I was moving really well and taking the ball early, dictating every point. That's why it (looked) like - not easy, but it (looked) good for me,'' he added.

Sowetan Live said in a report that Wawrinka was also able to regain his composure after he lost his cool and dominated the rest of the game.

"I was trying to keep the focus you know when you drop your level against Bellucci, it is tough. He started to play better and it started to be a really tricky match," Wawrinka was quoted by Sowetan Live as saying.

Bellucci, who had a 5-19 record prior to the game, also offered his opponent a hard time on the court as he took the fourth game of the third set. Wawrinka even termed it as ''one bad game.''

''I tried to focus more on my game and not on what he was doing. Tried to make him work a lot. I was playing a little bit smarter at the end of the match," he told the media after the match.

According to AP Sports, Wawrinka made a record at Flushing Meadows last year when he defeated defending champ Andy Murray. He is set to face Slovenia's Balz Kavcic in the third round of the tournament.

Other winners of the U.S. Open second round are Peng Shuai who stunned fourth seed Agnieszka Radwanska, Maria Sharapova, Johanna Larsson and Grigor Dimitrov among others.

Venus Williams, who is a two-time champ and seeded No. 19, also claimed victory against Timea Bacsinszky from Switzerland and is set to go against Sara Errani, BBC reported.