Nadal, Berdych win matches at ATP Finals

LONDON, Nov. 24 (UPI) -- World No. 1 Rafael Nadal and sixth-seeded Tomas Berdych claimed straight-set, round-robin victories Wednesday at the ATP World Tour Finals in London.

Nadal won six consecutive games in one stretch of a 7-5, 6-2 win over third-seeded Novak Djokovic after Berdych had beaten No. 8-seeded Andy Roddick 7-5, 6-3.

Those decisions left Nadal leading Group A with a 2-0 mark while Djokovic and Berdych are 1-1 and Roddick is 0-2 going into Friday's final matches of the round robin.

Djokovic was tied 4-4 with Nadal when he had a contact lens issue. After a lengthy stoppage of play, Djokovic returned and the players split two games. But then Nadal ran off six straight games, winning the first set and taking a commanding 4-0 lead in the second.

Roddick had dropped a tough match to Nadal Monday after being up a set and a break. But he didn't manage to get an advantage over Berdych, who saved both break-point situations he faced.

Group B round-robin play wraps up Thursday with No. 2-seeded Roger Federer (2-0) going against fourth-seeded Robin Soderling (1-1) and fifth-seeded Andy Murray (1-1) playing No. 7 David Ferrer (0-2).

The top two finishers in each group advance to Saturday's tournament semifinals.