World number one Rafael Nadal was handed a place in the last four of the Barcelona Open on Thursday after David Nalbandian was forced to withdraw from their quarter-final clash with a hip injury.
The Spaniard earlier thrashed unseeded Belgian Christophe Rochus 6-2, 6-0 and was due to play seventh-seeded Nalbandian in the last eight on Friday as he bids for a fifth straight title.
Nalbandian had booked his quarter-final place with a 6-3, 6-4 win over Spanish 10th seed Nicolas Almagro but tournament doctor Angel Ruiz-Cotorro said the Argentine sustained an inflammation of the right hip and had to withdraw from the event.
"He is not in the right condition to contest a match of the intensity of a quarter-final," Ruiz-Cotorro told a news conference.
The injury deprives top seed Nadal of the chance to level the head-to-head record between the pair at 2-2.
In their last meeting, in March, Nadal saved five match points before coming through 3-6, 7-6, 6-0 in a classic fourth-round encounter at the Indian Wells Masters.
"I'm sorry for him," the Spaniard said at a news conference. "It's never a nice thing to go through in this way but you have to see the positive side which is that I am in the last four."
Nadal faces the winner of Friday's match between Czech Radek Stepanek, who beat Swiss Stanislas Wawrinka, and Russian third seed Nikolay Davydenko, conqueror of Spaniard Feliciano Lopez.
"Both are difficult opponents," Nadal said.
"Stepanek has an unusual style and breaks up the play whereas Davydenko keeps the rhythm up all the time and is very hard to dominate.
"I'll be training a bit harder than normal tomorrow and that should be enough."
The Australian Open, Wimbledon and French Open champion was in brutal form against Rochus, breaking the Belgian's serve twice in the first set and three times in the second on the clay in the Catalan capital.
Nadal became the first man to win the Monte Carlo Masters five times in a row when he beat Novak Djokovic in Sunday's final and begins his attempt for a fifth consecutive French Open crown next month.
Second seed Fernando Verdasco reached the quarter-finals with victory over Czech Tomas Berdych and Chilean fifth seed Fernando Gonzalez also progressed against Argentine Juan Monaco.
Last year's losing finalist David Ferrer and 2004 winner Tommy Robredo will meet for a place in the semis after the Spanish pair each came back from a set down to beat Italy's Potito Starace and Russian Igor Andreev respectively.