Tennis legend Serena Williams is out of French Open in a big grand slam upset.

According to details, the 39-year old suffered a two set defeat 6-3 7-5 defeat by 21-year-old Elena Rybakina.

"It was definitely close," said Williams adding, "There is literally a point here, a point there, that could change the whole course of the match. I'm not winning those points - they could literally change everything."

Questions about how long she can keep competing at Grand Slams are inevitable but the 39-year-old is not giving much away.

"I'm definitely not thinking about it at all. I'm definitely thinking just about other things but not about that," said the three-time French Open winner.

Williams, 39, has not won a Grand Slam title since the Australian Open in 2017 and with seeds tumbling throughout this French Open, the draw seemed to be opening up for her.

Her next chance to equal Margaret Court's record of 24 Grand Slam singles titles comes at Wimbledon from 28 June.

Serena Williams has won the French Open singles title three times, in 2002, 2013 and 2015