Serena Williams is keeping busy this offseason moonlighting as a superhero.

In a post on her Facebook page today, the world No. 1 recounts her experience sitting in Chinese restaurant when she says an unnamed patron swiped her phone and dashed out the door, prompting Serena to leap a couple of chairs in a single bound and race down the sidewalk in pursuit.

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"Low and behold this common petty thief grabbed my phone and swiftly left. I looked at the chair, than shouted "Omg that dude took my phone!!" Serena posted on Facebook. "Not thinking I reacted (hence the superwoman photo) I jumped up, weaved my way in and out of the cozy restaurant (leaping over a chair or two) and chased him down."

Two things cannot elude the 21-time Grand Slam champion: phone thieves and drop shots.

"He began to run but I was too fast. (Those sprints came in handy) I was upon him in a flash!" Williams posted. "In the most menacing yet calm no nonsense voice I could muster I kindly asked him if he "accidentally" took the wrong phone. He stumbled on his words probably not expecting this to happen. While he was thinking of the right thing to say and eventually he said "Gosh you know what I did! It was so confusing in there. I must have grabbed the wrong phone."