Tomas Berdych and Juan Martin del Potro joined resting top seed Roger Federer in the Rotterdam Open quarter-finals.
Second seed Berdych advanced with only minimal effort as opponent Marcos Baghdatis quit with a left foot injury after 19 minutes on court while trailing 3-0 in their second round match.
But Del Potro, the number three seed making his debut here, had a battle on his hands before he finally got past Slovak Karol Beck 6-4, 7-5.
Federer moved easily into the last eight at the Ahoy stadium when scheduled second round opponent Mikhail Youzhny withdrew a day before their contest with a left foot injury.
Federer still had to go out and win his opening match against Frenchman Nicolas Mahut, which he did, 6-4, 6-4.
Del Potro had to overcome a slight bloody nose which required a medical time-out early in the contest with Beck.
Once that was sorted, it was back to work for the 2009 US Open champion, who advanced with nine aces - his last one earned two match points.
Del Potro needed almost two hours to move into a match with the winner from Serb seventh seed Victor Troicki and the last local standing in Jesse Huta Galung.
"He played so fast and hits with such a low bounce, I really had to keep up," said Del Potro of Beck. "It was tough.
"But I focused in the last game on trying to get an ace. I got one and I'm just glad that I'm through."
Frenchman Richard Gasquet, seeded fifth, continued his steady progress at his second tournament appearance, defeating Russian Alex Bogomolov 6-3, 6-2 while Italy's Andreas Seppi dispatched German Philipp Kohlschreiber 6-4, 6-2.
The 16th-ranked Gasquet improved his record to seven wins this season to next face Russian Niklay Davydenko.
AFPTags: tennis, sport, netherlands, australia First posted February 17, 2012 09:53:27