Rafael Nadal to play Roger Federer in Miami semis

Federer had much the easier passage as Gilles Simon withdrew from their quarter-final in Miami with a stiff neck after just three games.

Nadal beat Tomas Berdych 6-2 3-6 6-3, despite treatment to his shoulder.

In the women's draw, Maria Sharapova and Victoria Azarenka will meet in the final after coming through their semis.

Simon's retirement after just 10 minutes against Federer was greeted by jeers from the Miami crowd, but the Swiss had sympathy for his opponent.

The pair have met 22 times to date, with Nadal winning 14 times, and Friday will see them meet in a semi-final for only the fourth time.

Sharapova reached her first final of the year with an impressive comeback as she saw off German Andrea Petkovic 3-6 6-0 6-2.

The Russian former world number one made a slow start to her semi-final, setting the tone for the first set by double-faulting three times in her opening service game as 21st-seeded Petkovic pulled ahead.

However, Sharapova rallied emphatically, cutting out the errors as she reeled off 11 successive games to take the second set to love and put her in command in the third.

Petkovic won two games at the end of the final set but by then it was too late and Sharapova saw out the match to progress to her third Miami final.

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