World number one Rafael Nadal, taken the distance for the third match running, outlasted Frenchman Jo-Wilfried Tsonga 6-4, 6-7, 6-4 on Friday to reach the semi-finals of the World Indoor Tournament.
Nadal, who went to three sets against Simone Bolelli and Grigor Dimitrov earlier this week, next meets fifth seed Gael Monfils who beat French compatriot Julien Benneteau 7-6, 6-1.
World number four Andy Murray was 7-6, 4-6, 3-0 up on Marc Gicquel when the Frenchman was forced to retire with a groin injury.
The second-seeded Briton now plays unseeded Croatian Mario Ancic, who overcame 2007 champion Mikhail Youzhny of Russia 6-4, 6-2.
Nadal made a good start against seventh seed Tsonga, taking the opening set.
Tsonga, who hit 26 aces in the match, fought back to claim the second set on a tiebreak.
However, the Frenchman could not put pressure on the Spaniard's serve in the decider and Nadal clinched victory on his first match point.
"This was a completely different match from my first two ... today I played my best tennis so far in Rotterdam," Nadal told reporters after an encounter lasting two hours 40 minutes.
"I played against a very good opponent who showed form by winning a tournament (in Johannesburg) last week."
Murray was pleased with his display against Gicquel, who had entered the main draw as a 'lucky loser'.
"It was quite a high-standard match with entertaining tennis and it was satisfying he created only two break chances on my serve," said the Scot.
"I am happy with my game. I was hitting the ball much better than my previous two matches," added Murray, who trails Ancic 3-1 in head-to-head meetings.
Saturday's match will be Ancic's second semi-final in Rotterdam after Roger Federer prevented him reaching the final in 2005.
"If you only look at the score it seemed very easy today but I played really strongly on several crucial points," said Ancic after saving all seven break points against Youzhny.
"I am in good shape and full of confidence."