Nadal through to last-16 in Rome after Almagro retires with injury

Rafael Nadal eased into the last-16 of the Italian Open on Tuesday when his second-round opponent Nicolas Almagro retired after sustaining a knee injury early in the first set.

Nadal, who is the clear tournament favourite and looks to be in the form of his life on clay this season, raced into a 3-0 lead before Spanish compatriot Almagro felt his left knee with less than half an hour played.

Nadal is seeded fourth in Rome, where he is bidding for a record eighth title to go with his recent successes in Monte Carlo, Barcelona and Madrid, and will meet either the CzechRepublic's Jiri Vesely or American Jack Sock in the next round.

Japan's Kei Nishikori, the number seven seed, beat Spaniard David Ferrer 7-5, 6-2 earlier in the day and will play either Britain's Kyle Edmund or Argentine Juan Martin del Potro in the last 16.

Third seed Stan Wawrinka was also in action later on Tuesday against unpredictable Frenchman Benoit Paire, who beat him on clay in Madrid last week.