Serena Williams walked into a public tennis court this week in San Francisco and she spied on two men playing a friendly tennis match. She peered through the fence like so many fans do when she practices on a practice court.

Serena Williams finally managed to get the attention of the guys who predictabily reacted in disbelief and awe. The tennis star was with her dog and snapchat rolling, the grand slam champion challenged the two into impromptu hitting session.

Serena warned the two men that she doesn't have her Nikes. She showed off her high boots, but that shouldn't be a problem for her as back in 2004, Serena Williams famously warmed up at the U.S Open wearing black knee-high boots. Those boots were Nikes incidentally.

She eventually took that boot off before the U.S Open match, even if she would have wore them, it would have been against the customary tennis attire rule that's tennis's equivalent of no shirts, no shoes, no service. The bikini bottoms and a denim skirt were quite cool, she rocked the tournament wearing those.

The video of the pick-up public court game couldn't pick up on Serena Williams playing any points but it is noted that she was still undefeated, which implies eventually she won the game. The random guys in San Francisco have had pretty much the same amount of success against as her peers in the WTA.

The entire scene was documented on Serena Williams' snapchat, most of it was filmed by her fiance, co-founder of Reddit Alexis Ohanian. She was on a late-night walk with Ohanian and her dog named Chip. She finally says the moral of this story is you never know when she could be coming to a tennis near you, one for the fans.