Maria Sharapova set foot on a tennis court for the first time since her positive drug test at the Australian Open on Monday, smiling throughout an appearance in the World Team Tennis Smash Hits charity event in Las Vegas.

The Russian star, who last week earned a reduction in her drug ban that will allow her to return to tennis in April, played in two light-hearted doubles matches in the event at Caesar's Palace to benefit the Elton John AIDS Foundation.

Sharapova lost her doubles match with American youngster Taylor Johnson when they faced Martina Navratilova and Liezel Huber.