Melbourne, Jan 19 (IANS) Japan's Kei Nishikori defeated Portugal's Joao Sousa in straight sets on Saturday to book his place in the fourth round of the Australian Open.

The eighth seed overcame a tight start and routed his opponent 7-6(6), 6-1, 6-2 in two hours and six minutes, reports Efe.

"I love to play on this court. I feel very comfortable, and it's been three in a row playing here," Nishikori said after the match.

"Everything is doing well - I had a very good off-season, then winning Brisbane, it's been a good start to the year. I finished in three good sets today, I'm playing good tennis, and very much looking forward to next week," he added.

Nishikori coughed up a break in the opening game, but recovered to level up at 2-2.

Sousa saved a virtual set point to hold for 5-6 before Nishikori sent the opener into a tiebreak.

--IANS ajb/vm