Osaka's coach, Sascha Bajin, reacts to Serena's warning, Naomi's play

Court Report—Naomi Osaka wins the US Open:

NEW YORK—Naomi Osaka's coach, Sascha Bajin, says the umpire was not wrong to give Serena Williams a warning if she was getting coached, and denied giving his player instructions from the box.

Williams received a warning from the umpire when her coach, Patrick Mouratoglou, gestured to her from the stands during the final of the US Open. Coaching is not allowed in-play at Grand Slam events.

Asked by TENNIS.com if the warning was fair, Bajin did not question the ruling.

"If he was coaching her, I guess it was," he said. "But I don't know, I don't pay attention to the other side. I was just so focused on Naomi."

Speaking to ESPN, Mouratoglou admitted to breaking the rule, but said it was widespread in tennis.

"I'm honest. I was coaching," said Moratoglou. "I don't think she looked at me, but like 100 percent of the coaches in 100 percent of the matches.

"Sascha was coaching... Toni Nadal is coaching every single point and he's never given a single point."

Rafael Nadal has received warnings for coaching, but infrequently, and his uncle, Toni, has largely stopped accompanying him to events.

Bajin said he had not been coaching during the final, and praised Osaka's performance.

"It was beautiful, to see how composed she stayed during this whole match, how she didn't drop her level of play," he said. "And yeah, kind of stayed calm, the whole crowd going against her. Then the delays with whatever happened on court, she knew what she had to do."

A subsequent code violation for racquet abuse and then verbal abuse led to a point and game penalty for Williams, leaving Osaka a break up in the second set. The 20-year-old from Japan held serve the next game for a 6-2, 6-4 win.

Bajin was the longtime hitting partner of Williams until a few years ago, and began coaching Osaka this season. It was Osaka's first Grand Slam victory, and also his first as a coach, coming against a player she grew up idolizing and whose team he had previously been on.

"If it's Serena or not Serena, I personally don't care," he said. "But [beating] Serena in a Grand Slam final, not too many girls have done that, and that's a huge accomplishment."

It was Osaka's second victory against Williams.

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