Wawrinka, Nishikori battle into French Open second round

World number three Stan Wawrinka progressed through to the second round of the French Open following a straight-sets victory over Jozef Kovalik of Slovakia in the opening round of the men's singles event here on Tuesday.

After comfortably winning the first set, the Swiss maestro went down in the second before rebounding strongly to register a 6-2, 7-6 (8-6), 6-3 win over World No. 152 Kovalik in an exhilarating encounter that lasted almost two hours.

Wawrinka, the 2015 champion at the Roland Garros, will now take on Alexandr Dolgopolov of Ukraine in the second round.

Meanwhile, Japanese tennis star Kei Nishikori also made it to the second round after struggling past Australia's Thanasi Kokkinakis.

Eighth-seeded Nishikori bounced back from a set down to post a 4-6, 6-1, 6-4, 6-4 win over his Australian opponent in a clash that lasted more than three hours.

Elsewhere, former US Open champion Juan Martin del Potro thrashed fellow Argentine Guido Pella 6-2, 6-1, 6-4 in his first match at the tournament since 2012.

Del Potro will now lock horns with Nicolas Almagro of Spain for a place in the third round.