NEW YORK—Patrick Mouratoglou admits he tried coaching Serena Williams from the stands in tonight's US Open final.

But the veteran coach said Williams did not see his hand signals and charged Naomi Osaka's coach, Sascha Bajin, coached his charge throughout Osaka's 6-2, 6-4, sweep in the final as well.

More: Osaka Slams Serena In US Open Final

The 20th-seeded Serena was called for a game penalty for verbally abusing chair umpire Carlos Ramos after the veteran umpire hit her with two warnings—one for coaching and one for smashing her racquet.

Mouratoglou, who was captured by court-side cameras making a "move forward" gesture with both hands, told ESPN's Pam Shriver he did try to coach Williams, but said that's standard procedure for coaches in major finals.

"I'm honest. I was coaching," Mouratoglou told his ESPN colleague. "I don't think she looked at me, but like 100 percent of the coaches in 100 percent of the matches [coach].

"I was coaching, Sascha was coaching too. Toni Nadal is coaching every single point and he's never gave a single point."

Mouratoglou claims tonight's final was the first time he's ever been called for coaching.

"Not once in my life [have I been called for coaching] to be honest," Mouratoglou said. "And you can check the records. So it's strange to happen in a Grand Slam final. [Osaka] is a champion, no doubt, and Serena didn't play her best."

Asked her reaction to Mouratoglou's admission he coached, Williams replied "I'm trying to figure out why he would say that."

"We don't have signals," Williams said. "We have never discussed signals. I don't even call for on-court coaching." 

Photo credit: Christopher Levy