In other first round matches, at the World Indoor Tournament, second seed Nikolay Davydenko beat qualifier Jan Hernych while David Ferrer advanced with a victory over Italy's Simone Bolelli.
Rafael Nadal blasted past Serb Novak Djokovic 6-4, 6-4 to improve his record to 2-1 at the Masters Cup.
David Ferrer defeated Rafael Nadal while Novsk Djokovic was knocked out of the Shanghai Masters Cup.
World number two Rafael Nadal recovered from an unsteady start to overpower Marcos Baghdatis 6-4 6-4 in the Madrid Masters on Wednesday and set up a mouth-watering last-16 clash against Andy Murray.
Serbia's Novak Djokovic and Spaniard David Ferrer rolled into the US Open semi-finals for the first time in their careers.
The Spaniard beat fourth seed David Nalbandian of Argentina 7-6, 6-2.
World number one Roger Federer and Rafael Nadal reached milestones as they eased into he Monte Carlo Masters Series semi-finals on Friday.
Spaniards David Ferrer and Juan Carlos Ferrero also suffered first round shocks at the Valencia Open on Tuesday.
Top seed Amelie Mauresmo reached the semi-finals of the Nasdaq-100 Open after a 6-1, 6-4 win over tennager Ana Ivanovic on Wednesday.
Rafael Nadal was tested for the first time this week as he beat Italian Potito Starace 6-2, 7-5 on Friday to reach the semi-finals of the Barcelona Open and extend his record claycourt winning streak to 70 matches.
Former World No 1 Roger Federer returned from a 10-week layoff with a 6-3, 6-4 second-round victory against Spain's Guillermo Garcia Lopez at the Monte Carlo Masters on Tuesday.
The world number one crushed Spaniard David Ferrer in the first round of the Qatar Open to set up a clash with Briton Greg Rusedski.
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.
Rafael Nadal is the oldest title winner in the history of the clay-court tournament.
Novak Djokovic won a record-equalling 20th Grand Slam title by after winning this year's Wimbledon drawing level with long-time rivals Roger Federer and Rafael Nadal.
Resurgent Spanish great Rafael Nadal will have the rare privilege of playing on a court named after him when he meets Brazilian Rogerio Dutra Silva in the last 32 of the Barcelona Open on Wednesday.
Juan Martin del Potro is unlikely to be fit enough to play in next month's Australian Open, the Argentine told a news conference on Tuesday.
Factbox on Rafael Nadal, who beat Novak Djokovic 6-0, 6-2, 7-5 on Sunday to win a record-extending 13th French Open title:
Defending champion Novak Djokovic was handed a tough opening round at Wimbledon when Friday's draw paired him with Germany's Philipp Kohlschreiber.
Roger Federer does not figure among the top four in the men's tennis world rankings for the first time in ten years. The Swiss champion and holder of a record 17 Grand Slam titles slipped to No 5 in the latest rankings following a shock second round defeat by little-known Ukrainian Sergiy Stakhovsky at Wimbledon.
Britain's Wimbledon hope Andy Murray has to live with the very different pressure that comes with being labelled a shoe-in to reach the final after two of his main rivals suffered shock exits in early rounds.
Rafael Nadal has booked his place at the World Tour finals after winning a record eighth French Open title, the ATP said on Monday.
Factbox on Rafael Nadal, who beat Dominic Thiem to win his 12th French Open title:
Fabio Fognini pulled off a huge upset, stunning top seed and holder Rafael Nadal 1-6, 6-2, 7-5 in the Rio Open semi-final on Saturday.
If Rafael Nadal's Australian Open semi-final win over Greek sensation Stefanos Tsitsipas was one-sided, Novak Djokovic showed he could be even more brutal in his victory against Lucas Pouille on Friday.
Factbox on Rafael Nadal, who beat Dominic Thiem 6-4, 6-3, 6-2 to win his 11th French Open title on Sunday:
Novak Djokovic scraped over his first hurdle at the Rome Masters.
Defending champion Novak Djokovic survived a scare.
Spanish tennis player Rafael Nadal, who will play this week in the Rio Open, downplayed public concerns over risks linked to the Zika virus in the Brazilian city that will host the Olympics in August, saying "people are living completely normal lives."
Here is a factual guide on the man of the moment...
Factbox on Spaniard Rafael Nadal, who beat Swiss Stanislas Wawrinka 6-2, 6-3, 6-1 to win his 10th French Open title on Sunday.
Spaniard David Ferrer produced one of his finest performances to edge world number one and compatriot Rafael Nadal 6-3, 7-5 in the Paris Masters semi-final on Saturday and keep alive his hope of retaining his crown.
Seven-time Italian Open winner Rafael Nadal lost 7-6(7), 6-2 to Stanislas Wawrinka.
World number two Murray, who smashed a frame in anger in the final game, said the proximity of next week's Davis Cup final on a claycourt in Ghent had not been a factor in his defeat.
A summary of sports events and persons who made news on Thursday
Rafael Nadal's announcement on Friday that he will miss the ATP World Tour Finals because of appendicitis ended a difficult year for the Spaniard during which he has endured injury, illness and worrying defeats.
PHOTOS from day two of the Wimbledon championships at the All England Lawn Tennis and Croquet Club in London on Tuesday.