Roddick in Key Biscayne on Tuesday. (Reuters)

Miami: Roger Federer remained on course to complete the Miami-Indian Wells Masters Series double for the second consecutive year on Tuesday with victory over Dmitry Tursunov to reach the Nasdaq-100 Open quarter finals.

Champion at the Pacific Life Open in Indian Wells earlier this month, the Swiss top seed beat the Russian 6-3, 6-3 to notch up his 45th straight victory on US soil.

In women’s event, top seed Amelie Mauresmo of France got past Russian Nadia Petrova, seeded fifth 6-3, 6-1 to enter semi-finals while Russian 12th seed Svetlana Kuznetsova also made the last four with a 6-0, 7-6 win over Ai Sugiyama.

Fourth seed Andy Roddick ended the surprise run of Simon Greul, beating the German qualifier 6-3, 3-6, 6-2.

Greul, ranked 130th in the world, went into the match having knocked out Paradorn Srichaphan, Dominik Hrbaty and Tim Henman. The 24-year-old made Roddick work hard for his win, the American advancing on his third match point after a contest lasting one hour 33 minutes.

Croatian Mario Ancic and Ivan Ljubicic progressed with the minimum of fuss. Ancic, the 22nd seed, upset Russian fifth seed Nikolay Davydenko 7-5, 6-4 while number six Ljubicic swept past Belgian Christophe Rochus 6-3 6-1. (REUTERS)