Video: Serena Williams shares rare footage of father Richard with her daughter Olympia

Having withdrawn from the public eye in recent years, Richard Williams, the father of Serena Williams, was unable to escape his daughter's camera as she caught him sharing a moment with his granddaughter, Olympia.

The 23-time Grand Slam champion shared a video to her Instagram account on Tuesday, which featured her daughter Olympia, 4, riding a bicycle down the sidewalk while Richard looked on. The 79-year old Williams videotaped the moment on his own phone, while encouraging Olympia on her training bike.

"A rare sighting, the one and only G.O.A.T. still motivating," Serena captioned the clip. "King Richard, but I call him daddy." This is in reference to the upcoming film 'King Richard', which is based on her father's life and will premiere in theaters and on HBO Max Nov. 19.