Rafael Nadal took another step forward in his bid for a rare calendar-year Grand Slam on Monday by booking his spot in the Wimbledon quarter-finals with a commanding 6-4, 6-2, 7-6(6) win against Dutchman Botic van de Zandschulp. The All England Club, where the Spaniard has won two of his 22 majors, has been the least rewarding place for Nadal but he arrived this year having won the Australian and French Open titles back-to-back for the first time in his career. A third Wimbledon title and first since 2010 on the manicured lawns and a US Open triumph would see the Mallorcan claim the calendar slam -- a feat last achieved in 1969 by Australian great Rod Laver.