Following her US Open fourth-round exit, Naomi Osaka turned to a familiar face to fill a coaching void.

Osaka asked her father and original coach, Leonard François, to coach her during the Asian swing.

More: Osaka Wins Fifth Title in Beijing

Family ties have helped the former world No. 1 create resurgence.

The 21-year-old Japanese has captured back-to-back championships in her hometown of Osaka and in Beijing where she rallied past world No. 1 Ashleigh Barty to extend her winning streak to 10 matches.

Despite their success, Osaka says her father will not be her full-time coach.

Because dad gets too tight watching her play.

"He's always there, you know. But I don't think he can handle it," Osaka said of her father. "Like, not even just saying this, but he doesn't like watching my matches. I think it stresses him out because he, like, twitches every time I hit a ball.

"He said he'll take the [coaching] role very seriously, but I don't think it's a long-term thing.” 

Osaka, who split with coach Sascha Bajin after the Australian Open and parted company with coach Jermaine Jenkins after her US Open exit, credits her father, who often wears mirrored sunglasses while sitting in her support box, as being a positive presence who keeps things simple.

“The thing with my dad is he keeps it very simple," Osaka said. "He knows my personality because, like, he's my dad. Most of the time he doesn't even really say anything. He just waits for me to figure it out."

Photo credit: China Open Facebook