Robin Williams' smiling face, in a variety of his most well-loved characters, adorned the big screen at AT&T in a stirring tribute to the late award-winning actor.

Zak Williams, the oldest son of the beloved Academy Award winner and comedian, lofted an emotional ceremonial first pitch to Billy Crystal to start Game 5 of the World Series between Williams' San Francisco Giants and the Kansas City Royals on Sunday night.

Zak, joined at the AT&T Park mound by siblings Zelda and Cody, found Crystal's glove then erupted in joy. Zak raised both arms into the air before finding Crystal, an award-winning actor and close Williams friend, for an embrace.

A special tribute for Williams played on the main center-field scoreboard, featuring highlights of his films as well as photos of him from various visits to the ballpark — one with home run king Barry Bonds and Hall of Famer Willie Mays. A clip of Williams leading fans in a pregame chant also played, and Crystal got things going with his own chant of "Play ball!"

"We are honored to be here in support of the tribute to our father, someone who loved his hometown and especially the Giants," Williams' children said in a statement through the Giants. "For all of us, it is a tremendous delight and a little surreal to throw out the ceremonial first pitch of a World Series game for our team to our dad's best friend. We could not think of a better way to celebrate his memory. Let's go Giants!"

Williams, who lived in nearby Marin County, died Aug. 11 of an apparent suicide. He was 63.