Serena shows her emotions after overcoming a lost second set to win her comeback [GALLO/GETTY]

Returning to Grand Slam tennis after a year out with health problems, Serena Williams picked up where she left off with a winning display on Centre Court at Wimbledon, before bursting into tears.

Opening Tuesday's play on the showcase stage at the All England Club, the four-time champion overcame the gutsy play of Arvane Rezai to beat the French player 6-3, 3-6, 6-1.

"It's been a disaster year, but I've been praying," Williams said.

"To be able to come back at Wimbledon is pretty awesome. I didn't expect to play. And I didn't expect to even do anything.

"So I'm just excited. I've never cried with joy for anything."

The defending champion fought through a mid-match slump, re-establishing her authority in the third set with her big serve and powerful groundstrokes.

She showed why she is still considered a title favourite despite her long layoff, after two foot operations and blood clots on her lungs.

"I kept thinking, 'This is Wimbledon,'" she said.

After serving her 13th ace to close out the match, Williams buried her face in her towel and sobbed as she sat on her courtside chair.

She was still crying as she walked off court.

Elsewhere in the first round, fifteenth seed Jelena Jankovic was knocked out by Spain’s Maria Jose Martinez Sanchez 5-7, 6-4, 6-3.

The Serb has never progressed past the fourth round at Wimbledon.

In the men's draw, American Andy Roddick beat Andreas Beck of Germany 6-4, 7-6, 6-3 as he bid to add to the only Grand Slam title he won at the US Open in 2003.

He reached the Wimbledon final in 2004, 2005 and 2009, losing to Roger Federer on each occasion.

Swiss Federer was playing Kazakhstan's Mikhail Kukushkin later on Tuesday.

Source: Agencies