The most anticipated match so far at the 2018 French Open was over before it began on Monday after Serena Williams retired just before her showdown with Maria Sharapova, citing a pectoral injury.

Williams, who had been rolling at Roland-Garros in her first Grand Slam tournament since giving birth to her daughter, said that the pain was limiting her ability to serve.

For Sharapova, she earns her first Grand Slam quarterfinal appearance since 2016, when Williams defeated her at the Australian Open.

Next up for Sharapova is Garbine Muguruza, who also moved on due to a retirement. Lesia Tsurenko was forced to stop Monday after just two games against Muguruza because of a leg injury.

The No. 3-seeded Muguruza missed the quarterfinals at the US Open and Australian Open after her win at Wimbledon last year, so she’s hoping to make an even deeper run to replicate that success.

Elsewhere Monday, top-seeded Simona Halep was dominant in a straight-sets win over Elise Mertens. Halep won six break points and capitalized on four double faults from Mertens, who struggled overall. At one point, Halep won eight points in a row. Mertens did herself no favors with 22 unforced errors, and Halep needed only 16 winners.

Next up for Halep is Angelique Kerber, who defeated Caroline Garcia in straight sets. Kerber and Halep are 5-5 against each other head to head, with Halep winning their meeting earlier this year in Melbourne. It took Halep three sets and a tiebreaker, however, and Kerber has only looked challenged by Kiki Bertens to this point. She’ll try to advance to the French Open semifinals for the first time in her career.

Maria Sharapova
Maria Sharapova
In a bit of bonus tennis, No. 2 Caroline Wozniacki was bounced after a nightmare return to a match from Sunday that was delayed due to darkness. Wozniacki dropped three straight games to Daria Kasatkina to lose 7-6, 6-3. She’ll have to wait for Wimbledon to pursue her second career Grand Slam after winning the Australian Open in January.

In the men’s bracket, one question looms large: Who will challenge Rafael Nadal? Nadal routed Maximilian Marterer in straight sets to advance to the quarterfinals in pursuit of his 11th French Open title and his second in as many years. At 32, Rafa looks as dominant as ever, and with no Roger Federer in the bracket, he’s the heavy favorite to win again at Roland-Garros.

With that being said, his next challenger is Diego Schwartzman. Schwartzman took down Kevin Anderson in an epic 1-6, 2-6, 7-5, 7-6, 6-2 comeback. Twice Schwartzman needed seven games just to survive, and after he took the fourth set with a 7-0 tiebreaker, Anderson never recovered. The final set was all Schwartzman, who will now take on his toughest challenge of the Open in Nadal.

Juan Martin del Potro took down the last American man standing, John Isner, in straight sets. Despite 12 aces from the ever-powerful Isner, 42 unforced errors were far too many to overcome.

Del Potro will face off against Marin Cilic, who staved off Fabio Fognini 6-4, 6-1, 3-6, 6-7, 6-3. Seven breaks from Cilic proved to be the difference in the match, in an ugly match for both sides. Cilic had 54 unforced errors, whereas Fognini had 68. It was an ugly way to end the day, but the No. 3 seed was able to move on.

Source: Kevin Skiver|| CBS