The World number one Rafael Nadal advanced to the third round of the Cincinnati Masters with a 6-2 7-5 victory over American Taylor Dent.
In the first real upset of the tournament, Nadal's compatriot eighth seed Fernando Verdasco lost to 36th-ranked American Mardy Fish.
Nadal will face Julien Benneteau in the next round after the Frenchman defeated Switzerland's Stanislas Wawrinka 6-4 6-2.
The Serbian world number three Novak Djokovic also progressed in straight sets, defeating compatriot Viktor Troicki 6-3 7-5.