Spain's Rafael Nadal cruised to a two-set victory in his singles debut at the Brazil Open here late Thursday but then the 11-time grand slam winner blasted the ATP Tour for its choice of balls.

The former world number one needed only 78 minutes to prevail over Brazilian Joao Souza, ranked 140th in the world, 6-3, 6-4.Nadal advanced to Friday's quarterfinals where he will face Argentine Carlos Berlocq, who beat eighth seed Albert Ramos 7-6 (9/7), 6-4.

He said he made a "good decision" by withdrawing Wednesday from a scheduled doubles match he was to have played with Argentina's David Nalbandian against Argentine Horacio Zeballos and Austrian Oliver Marach.Nadal said he was able to rest his knee, after a tough week of play in Chile last week, and made clear that his priority here was to play the singles event.

The $455,775 Brazil Open is part of the Latin American clay court circuit, along with the Vina del Mar and the Mexico Open in Acapulco where Nadal plans to play later this month.He said he did not feel any particular discomfort during the match.Nadal, who reached both the singles and doubles finals Sunday at his comeback event in Vina del Mar, Chile, is the top seed at this week's event here.

The world number five, who has claimed seven of his 11 Grand Slam titles on the clay courts of Roland Garros, won the Brazil Open in 2005 when it was held in Costa do Sauipe in eastern Bahia state.The tournament was moved to Sao Paulo last year when Spaniard Nicolas Almagro won