Updated

Jo-Wilfried Tsonga and Nicolas Almagro were among the winners Monday on the first day of play at the Japan Open.

The second-seeded Tsonga knocked off fellow Frenchman Gael Monfils, 6-3, 7-6 (10-8), while the sixth-seeded Almagro needed a pair of tiebreakers to squeeze past German qualifier Benjamin Becker, 7-6 (7-4), 7-6 (7-3).

Tsonga, the 2009 Tokyo champ, is playing just his second tournament after recovering from a knee injury suffered at Wimbledon. He was the runner-up in Metz eight days ago, falling to fellow Frenchman Gilles Simon in the final.

Almagro struggled all summer after leaving the clay. The Spaniard was a semifinalist at the German Open on the slow surface in July, but then lost four straight matches on hard courts, including a first-round ouster at the U.S. Open, prior to Monday's win.

Two unseeded winners Monday were Finland's Jarkko Nieminen and Alexandr Dolgopolov of the Ukraine. Nieminen topped Argentina's Juan Monaco, 7-6 (7-4), 6-1, while Dolgopolov eased past Germany's Daniel Brands, 6-3, 6-1.

First-round play will continue Tuesday. Top-seeded Juan Martin del Potro will meet Marcos Baghdatis of Cyprus and defending champion Kei Nishikori of Japan will take on Austrian veteran Jurgen Melzer.