WASHINGTON, March 28 (Xinhua) -- Roger Federer remained on course to complete the Miami-Indian Wells Masters Series double for the second consecutive year on Tuesday after beating Dmitry Tursunov in straigth sets to reach the Nasdaq-100 Open quarter-finals.
Champion at the Pacific Life Open in Indian Wells earlier this month, the Swiss top seed downed the Russian 6-3 6-3 to notch up his 45th straight victory on US soil.
"It's always more difficult to play a guy for the first time," Federer told reporters after securing his 25th victory of the season against just one loss.
"I did well today. He's dangerous and I needed to play a solid game. I'm very pleased. I had to make adjustments for a setting sun and the wind out there."
In the women's event, Russian 12th seed Svetlana Kuznetsova became the first player to reach the semi-finals with a 6-0 7-6 triumph over Ai Sugiyama of Japan.
Earlier, men's 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.
Roddick, the 2004 champion, has yet to reach a final this season.
Croatian Davis Cup teammates Mario Ancic and Ivan Ljubicic progressed with ease.
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.
Ljubicic, who hit 13 aces, next meets unseeded Argentine Agustin Calleri, a 3-6 6-3 7-5 winner over 16th seed Nicolas Kiefer of Germany. Enditem
