Patrick Mouratoglou says he'd bend tennis rules at 2019 US Open

Serena Williams' coach, Patrick Mouratoglou, says he would break the rules against on-court coaching again despite the trouble it caused at last year's US Open final.

Williams was given a code violation by umpire Carlos Ramos after Mouratoglou was seen instructing her from the crowd during the American's defeat to Naomi Osaka.

Williams went on to receive two further code violations before calling Ramos a “liar” and accusing him of being sexist.

“Do I regret [having coached]？ Not at all,”Mouratoglou told reporters on Sunday, via ESPN. “For me, I didn't do anything bad. I just did what all the coaches do.”

Williams plays Wang Qiang in the quarterfinals on Tuesday.

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Serena Williams' coach, Patrick Mouratoglou, says he would break the rules against on-court coaching again, despite the controversy it caused in the American's 2018 US Open final defeat to Naomi Osaka.

Williams was given a code violation when Mouratoglou was seen instructing her from the stands in last year's final.

The call from umpire Carlos Ramos sparked an on-court row with Williams, which later resulted in the 23-time Grand Slam champion calling Ramos a “liar” and accusing him of being sexist.

“I would do the same tomorrow,” Mouratoglou told reporters on Sunday, according to ESPN. Really. 100 percent. And if I'm penalized again, I think it's unfair the same way.

“Do I regret [having coached]？ Not at all. Not at all. For me, I didn't do anything bad. I just did what all the coaches do.”

Mouratoglou also insisted that it was unusual for his player to be slapped with a code violation for such actions, with umpires usually happy to turn a blind eye.

“I did it once,” he said. “Nobody gives a warning for the first time. They just tell you, 'Be careful.' Actually tell you to be careful usually after four or five times. Anyway, so I think it was completely unfair.”

Read more: Serena Williams said 'I don't know who that is' when asked about the 2018 US Open umpire who caused her infamous meltdown

Fortunately for Williams and Mouratoglou, they are unlikely to collide paths with Ramos at this summer's tournament, after the Portuguese umpire was banned from chairing any of Serena Williams', or her sister Venus', matches.

The United States Tennis Association told The Guardian last month it would separate the trio for the benefit of the tournament.

Read more: Alexis Ohanian wore a drug awareness shirt to watch Serena Williams play Maria Sharapova, who was once suspended for using a banned substance

Williams has advanced to the quarterfinals of this year's tourmament having beaten the Croatian player Petra Martic 6-3, 6-4 on Sunday.

Williams now faces 18th seed Wang Qiang on Tuesday.