Nadal, Federer reach third round at Australian Open

Melbourne, Australia ( - World No. 1 Rafael Nadal and Roger Federer were easy second-round winners Thursday at the Australian Open.

Nadal beat Aussie Thanasi Kokkinakis 6-2, 6-4, 6-2 in a roof-covered Rod Laver Arena. The Spaniard captured his only title at the year's first Grand Slam in 2009.

The searing heat on Day 4 resulted in the tournament's extreme heat rule being put into effect, suspending the action on the outside courts.

The sixth-seeded Federer, a four-time Australian Open champ, played with the roof over the court at Hisense Arena and dismissed Slovenia's Blaz Kavcic, posting a 6-2, 6-1, 7-6 (7-4) victory.

Tenth-seeded Frenchman Jo-Wilfried Tsonga topped Brazilian qualifier Thomaz Bellucci 7-6 (8-6), 6-4, 6-4. The match on Hisense Arena began under the sun and was completed with the roof closed.

Japan's Kei Nishikori also advanced to the third round. The 16th seed handled Serbian Dusan Lajovic 6-1, 6-1, 7-6 (7-3) prior to the suspension of play. Nishikori's next opponent will be American Donald Young, who outlasted 24th-seeded Italian Andreas Seppi 6-4, 2-6, 6-3, 4-6, 7-5.