Tsonga, Ljubicic in Rotterdam semis
Jo-Wilfried Tsonga was handed a walkover after fourth seed Tomas Berdych pulled out because of flu.
Rotterdam: Frenchman Jo-Wilfried Tsonga will face Croatia's Ivan Ljubicic for a place in the World Indoor tournament final after they had contrasting paths through the quarter-finals on Friday.
Tsonga was handed a walkover after fourth seed Tomas Berdych pulled out suffering with flu but Ljubicic had to sweat for two hours and 24 minutes for a 6-4 6-7 7-6 victory over unseeded Marcos Baghdatis.
Holder and top seed Robin Soderling plays Russian Mikhail Youzhny and Marin Cilic takes on Victor Troicki in the remaining quarter-finals later on Friday.
Ljubicic, runner-up in the Dutch port city in 2005 and 2007, squandered a chance to dismiss Baghdatis in straight sets when he netted on match point in the second set tiebreak but recovered to hold off the Cypriot in the decider.
"It was a strange match in which I knew I had to take a lot of risks to beat him," the 31-year-old Ljubicic told reporters.
"I felt really comfortable after winning the first set but then I missed some crucial points in the tiebreak.
"This is a great win for me as I lost four times previously to Marcos."
Baghdatis had knocked out second seed Andy Murray in the opening round.