Australian Open runner-up Fernando Gonzalez suffered a surprise defeat at the Estoril Open, going down to Paul-Henri Mathieu in round one.

The Chilean, ranked six in the world, lost 6-2 6-4 to Mathieu, who won his third title in Casablanca last week.

"When you win a tournament that gives you a lot of confidence, so this helped for sure," said Frenchman Mathieu.

"Today I was feeling good on the court. I won five matches, six with today's win, so it's good for the confidence."

Fifth seed Richard Gasquet of France made it into the second round with a 6-3 6-3 victory over Max Mirnyi.

Top seed Nikolay Davydenko and Tommy Robredo's matches were delayed until Wednesday due to heavy rain.