Kei Nishikori (AFP)
Rio - Kei Nishikori sailed into the quarter-finals of the men's tennis singles at the Rio Olympics on Thursday, beating Slovakia's Andrej Martin in straight sets.
Martin proved no match for the in-form Japanese star, who powered to a 6-2, 6-2 victory in just 68 minutes.
There was a slight scare for Nishikori when Martin was able to regain an early lost break at 0-2 by hitting back with a break of his own, but he soon regained his composure, claiming two further breaks to wrap up the first set comfortably.
The second set saw Nishikori break twice more to seal the victory and set up a quarter-final match with Frenchman Gael Monfils, who came from a set down to defeat Croatia's Marin Cilic 6-7 (6-8), 6-3, 6-4.
Also advancing was Wimbledon champion Andy Murray, who survived a second-set blip to defeat Italy's Fabio Fognini 6-1, 2-6, 6-3.
Murray looked on course for the simplest of wins after racing through the first set and finding himself a break up in the second, but a loss of concentration saw Fognini come roaring back to level the scores courtesy of three successive breaks.
The Italian then broke again at the start of the third to open up a 3-0 lead, but just as he looked down and out, Murray was able to regather himself and regain control, rattling off the last six games in a row to wrap up the result in two hours and 10 minutes.
The Scot moves on to face American Steve Johnson, who dispatched Russian Evgeny Donskoy 6-1, 6-1 earlier in the day.