World number nine Juan Martin Del Potro posted an opening win over Australia's Marinko Matosevic to reach the third round of the ATP/WTA Indian Wells event, which has been hard hit by a stomach virus epidemic.
Argentina's Del Potro defeated the world number 129 Matosevic 7-5, 6-2.
Frenchman Gael Monfils was the highest-profile victim of the illness - which tournament officials were quick to say had nothing to do with their food service - withdrawing before his match with Nikolay Davyenko.
The Russian went on to defeat German lucky loser Bjorn Phau 7-5, 6-2.
Monfils was one of six players who have either pulled out or quit a match in the past several days due to the illness.
The tournament organisers found medical evidence for their theory that food service is not involved.
On court, Germans split the difference, with women's 14th seed Julia Goerges beating Anabel Medina Garrigues of Spain 6-3, 6-4 to next play either top seed Victoria Azarenka, who downed two-time finalist Svetlana Kuznetsova 6-1, 6-2.
In men's play, Spaniard Marcel Granollers beat German veteran Tommy Haas 6-3, 2-6, 6-3.
Granollers will next face compatriot and world number two Rafael Nadal, who routed Leonardo Mayer of Argentina 6-1, 6-3.
AAPTags: tennis, sport, united-states First posted March 12, 2012 11:23:44