Paris ? Injuries got the better of Rafael Nadal and Roger Federer in the Paris Masters quarterfinals Friday.

Nadal retired due to a knee injury after losing the first set 6-1 against sixth-seeded Nikolay Davydenko, just hours after Federer pulled out against 11th-seeded James Blake because of a sore back.

In today’s semifinals, defending champion David Nalbandian meets 2006 champ Davydenko, and Blake will try to stop Jo-Wilfried Tsonga from becoming the first French winner since Sebastien Grosjean in 2001.