Miami, FL (SportsNetwork.com) - Defending champion Novak Djokovic won his opening match at the Miami Open on Saturday, beating Slovakian Martin Klizan 6-0, 5-7, 6-1.

The top-seeded Djokovic is a four-time champion at this Masters 1000 event.

No. 4 seed Kei Nishikori and No. 5 seed Milos Raonic each beat Russians in their opening matches. Nishikori needed just 69 minutes to roll to a 6-2, 6-1 victory over Mikhail Youzhny, while Raonic defeated Teymuraz Gabashvili 6-1, 6-4.

Also advancing with second-round wins were No. 6 seed David Ferrer, No. 9 seed Grigor Dimitrov and No. 11 seed Jo-Wilfried Tsonga.

Tsonga outlasted American Tim Smyczek 6-4, 3-6, 6-3 in the French vet's 2015 debut. He had been sidelined because of a right arm injury and his win sets up a third-round bout with 17th-seeded countryman Gael Monfils, who edged qualifier Filip Krajinovic in a third-set tiebreaker.

Monfils played his first match in three weeks after recovering from a knee injury.

No. 13 seed Roberto Bautista Agut, No. 14 seed Ernests Gulbis, No. 16 seed Tommy Robredo, No. 19 seed Pablo Cuevas and No. 20 seed Ivo Karlovic were eliminated Saturday.

American Jack Sock knocked off a seeded player, handling No. 21 Italian Fabio Fognini by a 7-6 (7-4), 6-1 score.

Fellow American John Isner, seeded 22nd, also advanced via a 6-3, 6-4 verdict over wild card Andrey Rublev.

The winner of this prestigious hardcourt event will claim $900,400.