Spain's Rafael Nadal had his hands full from beginning to end but pulled out a 7-6 (7-3), 7-5, 7-6 (7-3) victory Monday over Japan's Kei Nishikori to advance to the quarterfinals of the Australian Open.

Nishikori used well-disguised and powerful ground strokes to put the world No. 1 on the defensive during numerous points throughout the match, which lasted over three hours, but lacked the wherewithal to get over the hump against the battle-hardened veteran.

In addition to the challenge posed by his opponent, Nadal also was flustered by two time violations called by chair umpire Eva Asderaki. He also lost his serve on four occasions, broke a lace on his left shoe, needed to have his left hand re-taped and had to call for the trainer at the end of the second set.

But he got through thanks mainly to unforced errors by the Japanese No. 16 seed, who committed 51 compared to just 28 for Nadal. Both players struck an equal number of winners - 36 - over the course of the match.

Nadal's serve also was a major factor, as the Spaniard put 71 percent of his first serves in play, won 76 percent of those points and threw down 12 aces.

He still lost serve four times, however, due to a poor 39 percent winning percentage on second-serve points.

"I think I played very focused, fighting for every ball. Kei played fantastic match, in my opinion. Just a few mistakes in some moments that was tough ones. But for the rest, he played very aggressive, he went for the shots," Nadal said in the post-match press conference.

"He came on court with determination to take the ball very early and go for the winners. He really had the right feelings to do it. So just was a tough match, a very important win."

Next up for Nadal in Wednesday's quarterfinals will be fast-rising Bulgarian Grigor Dimitrov, a 6-3, 3-6, 6-2, 6-4 winner Monday over Spain's Roberto Bautista Agut.

In other results Monday, four-time champion Roger Federer, the No. 6 seed, continued his impressive romp through the draw, turning a much-anticipated fourth-round contest against 10th-seeded Frenchman Jo-Wilfried Tsonga into a lopsided 6-3, 7-5, 6-4 victory.

Federer's quarterfinal opponent will be Scottish world No. 4 Andy Murray, who overcame a third-set hiccup to top Frenchman Stephane Robert 6-1, 6-2, 6-7 (6-8), 6-2.

In women's singles, No. 2 seed Victoria Azarenka of Belarus cruised past American Sloane Stephens 6-3, 6-2 in a contest that did not live up to the pre-match hype.

In the quarterfinals, she will next play Poland's Agnieszka Radwanksa, who easily defeated Spain's Garbiñe Muguruza 6-1, 6-3.

The other women's quarterfinal contest will pit Romania's Simona Halep, a 6-4, 2-6, 6-0 winner over Serbia's Jelena Jankovic, against Slovak Dominika Cibulkova, who stunned third-seeded Russian Maria Sharapova 3-6, 6-4, 6-1. EFE