Serena Williams dubbed herself a "superhero" after chasing down a man whom she believed attempted to steal her phone in a restaurant on Tuesday.
The world number one cut short her season after the agony of a sensational US Open semi-final defeat to Roberta Vinci in September, which ended her hopes of winning a first calendar Grand Slam.
Williams' coach Patrick Mouratoglou this week revealed that the 21-time grand-slam champion opted to take a break as she was troubled by knee injuries and depression.
While the 34-year-old American has been out of action on the court, she was involved in high drama off it and proved she could be returning to full fitness by catching up with a man who picked up her phone and headed for the exit as she dined with a friend.
She revealed in a lengthy post on Facebook: "He began to run but I was too fast. (Those sprints came in handy) I was upon him in a flash!
"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.
"Meanwhile My phone was ringing, my superhero sidekick quailman was face timing me so he could not possibly deny the allegations. I swiftly thanked him and left.
"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.
"Always listen to your superhero inner voice. Always keep your things close! Fight for what's right. Stand for what you believe in! Be a superhero!
"When I got back into the restaurant I received a standing ovation. I was proud. I just showed every man in there I can stand up to bully's and other men. It was a win for the ladies!"