Japan's Kei Nishikori advanced to the quarterfinals at Wimbledon for the second straight year on Monday following a fourth-round victory over Mikhail Kukushkin of Kazakhstan.

The eighth-seeded Nishikori claimed a 6-3, 3-6, 6-3, 6-4 win over the world No. 58 Kukushkin on No. 2 Court at the prestigious grass-court major. He will face second-seeded Roger Federer in his campaign to reach the Wimbledon semifinals for the first time.

"I kept patient although this was a tough match to close out," Nishikori said. "I was hanging in there and waiting for chances."

"I'll need to elevate my game further (for coming rounds) to compete against the top players in the world."

Nishikori gained a decisive early break in the fourth game of the opener, but in the second set he lost serve late and allowed Kukushkin to level the match.

After securing the only break of the third set to go up 5-3, Nishikori held serve at deuce to retake the lead.

In the final set, neither player managed to hold serve through the first five games. Nishikori went up 4-2 with the set's first successful hold, and three games later mustered an ace on the way to double match point.

Kukushkin eked out another point, but his forehand return at 40-30 sailed wide to give Nishikori the match in 2 hours, 43 minutes.

The world No. 7 Nishikori has now made it to the last eight or better in five consecutive Grand Slams dating back to his showing at Wimbledon last year, when he reached the quarterfinals for the first time but lost in four sets to Serbia's Novak Djokovic.

Nishikori is the only Japanese singles player remaining at this year's Wimbledon. Former world No. 1 Naomi Osaka made an early exit after a straight-sets loss to Yulia Putintseva of Kazakhstan in the women's competition.