Six-time Grand Slam champion Rafael Nadal advanced to the third round of the US Open on Friday by defeating Germany's Nicolas Kiefer 6-0, 3-6, 6-3, 6-4.

The third-seeded Spaniard, trying to complete a career Grand Slam with a US Open crown, will next face 32nd-seeded compatriot Nicolas Almagro for a berth in the round of 16.

Reigning Australian Open champion Nadal missed more than two months with knee tendinitis, unable to defend his 2008 Wimbledon title, but returned three weeks ago and showed top form in his first two matches.