Only three men have won more matches (Jimmy Connors, Ivan Lendl and Guillermo Vilas).

WSJ: Heard on the Field

Federer, seeded second, cruised to his 56th victory at the tournament, leaving him just two wins behind the record jointly held by Guillermo Vilas and Nicola Pietrangeli.

CNN: Cash: Only injury can deny Nadal in Paris

The 25-year-old can boast 35 trophies on clay in his career, behind only Argentina's Guillermo Vilas (45 titles) and Austrian Thomas Muster (40) in the all-time list.

CNN: STORY HIGHLIGHTS

Del Potro, who is currently ranked seventh in the world, is the second Argentine to win in Rotterdam after Guillermo Vilas, who triumphed in 1982 and finished runner-up the following year.

CNN: Del Potro rampant in Rotterdam

One more win will take Djokovic level with John McEnore's record start to a year from 1984, and within three victories of the best-ever winning streak in tennis, set by Guillermo Vilas in 1977 at 46.

BBC: French Open: Djokovic and Federer reach last eight