Maria Sharapova retired with injury in her second-round match in Rome, just hours after she was denied a wild card for the French Open, while defending champion Andy Murray crashed to a heavy defeat in his opener against Fabio Fognini on Tuesday.
Roger Federer announced Monday he will skip Roland Garros to better prepare for the grass and hard court seasons.
Rafael Nadal's flawless record on clay this season continued as he outgunned the impressive Dominic Thiem to win the Madrid Masters for a fifth time 7-6 (10/8), 6-4 on Sunday.
A much happier Nick Kyrgios sent Australia into the Davis Cup semi-finals when he beat American Sam Querrey in the first of the reverse singles in Brisbane on Sunday.
Roger Federer defeated long-standing rival Rafael Nadal 6-3, 6-4 to win the Miami Open on Sunday and continue his outstanding start to the year.
Roger Federer dramatically fought his way into the Miami Open semi-finals with a 6-2, 3-6, 7-6 (8/6) victory over Czech 10th seed Tomas Berdych on Thursday.
Unseeded Italian Fabio Fognini upset second ranked Kei Nishikori 6-4, 6-2 on Wednesday to earn a Miami Open semi-final clash with Rafael Nadal.
Top seed Stan Wawrinka crashed out of the Miami Open on Tuesday falling 4-6, 6-2, 6-1 to German young gun Alexander Zverev, who booked his first Masters 1000 quarter-final.
In-form Roger Federer powered his way into the fourth round of the Miami Open with a 6-3 6-4 win over Argentina's Juan Martin del Potro on Monday.
Roger Federer's comeback from injury has been so successful that his compatriot Stan Wawrinka believes he can become the oldest world number one in history at the age of 35.