Serena Williams has always been a superstar, but now she’s calling herself a superhero.

The tennis champ put her rigorous training to work Tuesday when she chased down a man who tried to swipe her cell phone in a busy San Francisco restaurant.

“So this guy is standing next to me and something (I have now dubbed my SUPERHERO sense) told me to watch him,” Williams wrote on social media Wednesday. “My phone was sitting in the chair but I just didn’t feel right.”

Williams said the man gave her an “eerie feeling” as she watched him wander around the restaurant, trying to figure out what he was doing there.

“Th[e]n when least expected low and behold this common petty thief grabbed my phone and swiftly left.”

But Williams chased the thief down — sprinting after him before calmly asking if he took the wrong phone by accident.

He hesitated for a moment before saying, “Gosh you know what I did! It was so confusing in there. I must have grabbed the wrong phone.”

When she returned to the restaurant, she received a standing ovation, which made her proud.

“Superhero? Maybe? Or HELL YEA!! I’ve got the speed the jumps, the power, the body, the seduction, the sex appeal, the strength, the leadership and yet the calm to weather the storm.

Williams used the story to encourage her female followers to always stick up for themselves.

“Just because you are a lady don’t be afraid to step up to any challenge and not be a victim but a hero,” she wrote.

Williams also thanked her superhero sidekick quailman, but it’s unclear who that was referencing — though she did tag fellow tennis star Caroline Wozniacki and her big sis Venus in the Facebook post.

“Always listen to your superhero inner voice,” Williams advised.