Leander Paes, who turned 42 two days back, has entered the semi-finals of the Men's Doubles at the ATP Aegon Championships. Paes pairing with Canadian Daniel Nestor disposed off the challenge of unseeded Spanish duo of Marc Lopez and Rafael Nadal in straight sets 7-6, 6-4 in the quarterfinals of the grass court tournament last night at the Queen's Club, London. The duo will be playing against second seeds Marcin Matkowski of Poland and Nenad Zimonjic of Serbia in the semifinals tomorrow.