BARCELONA Rafa Nadal was less than his dominant best on the clay at the Barcelona Open on Thursday but was still good enough to secure a 6-2 6-3 win over Colombian wildcard Robert Farah and set up a quarter-final clash against Janko Tipsarevic."The truth is that there are few easy matches on the tour,” world number two Nadal, chasing a seventh Conde de Godo trophy in eight years, said in an interview with Spanish television."He serves fast and very well and obviously that makes it tough but I am in the quarter-finals with positive feelings and let’s see what happens tomorrow, which will be more difficult.”Nadal, fresh from winning a record eighth successive Monte Carlo Masters crown, was joined in the last eight by second seed Andy Murray after the Briton thumped Farah’s unseeded compatriot Santiago Giraldo 6-1 6-2.Murray has a poor record at the event in the Catalan capital and has failed to get past the second round in his three previous appearances.