MOSCOW, June 4. /TASS/. US tennis player Serena Williams has pulled out of her fourth-round match with Russia’s Maria Sharapova who will now progress to the quarter-finals of the French Open tournament.

The American tennis player, who is the 23-time Grand Slam champion, was set to face Sharapova on Monday. Williams has withdrawn from competitions for the 16th time in her tennis career and for the first time from the grand slam tournament. She cited a problem with her pectoral muscle as the reason for her decision.

"I unfortunately have been having some issue with my pec muscle," the tournament’s press office quoted Williams as saying.

"It's very difficult, because I love playing Maria," she added.

"So it's extremely disappointing. But also, I made a promise to myself and to my coach and to my team that if I'm not at least 50% ready, then I probably shouldn't play," Williams said.

In the quarter-finals, Sharapova will play the winner of the fourth-round showdown between Garbine Muguruza (Spain) and Lesia Tsurenko (Ukraine).

Sharapova is Russia’s most decorated tennis player having won a total of five Grand Slam tournaments, namely the Australian Open in 2008, the French Open in 2012 and 2014, Wimbledon in 2004 and the US Open in 2006. She also clinched the silver in the 2012 Summer Olympics in London and was the 2008 Federations Cup champion.

After the 15-month long suspension, imposed in 2016 for violating anti-doping regulations, Sharapova made her comeback to tennis in April 2017.

Last October, Sharapova won the 2017 WTA Tianjin Open in China and it was her first tournament to win since May 2015.