Melbourne, Australia (SportsNetwork.com) - World No. 1 Rafael Nadal, Wimbledon champion Andy Murray and four-time Australian Open titlist Roger Federer were among Monday's fourth-round winners at Melbourne Park.
Nadal, who missed last year's Aussie Open due to a knee injury, was tested mightily by Kei Nishikori, but the mighty Spaniard staved off his 16th-seeded Japanese counterpart to claim a 7-6 (7-3), 7-5, 7-6 (7-3) triumph that took more than three hours to complete at Rod Laver Arena.
The 13-time major champion Nadal was broken twice by Nishikori in the third set -- receiving a time violation from the chair umpire in one of the games.
"Normally I have a good self-control on court, and it's true that the moment was a very critical one," Nadal said of the time penalty.
Nadal also tripped in the first set and tumbled to the court, prompting him to head to the locker room to change shoes.
The 2009 titlist and 2012 Melbourne runner-up will next face 22nd-seeded Bulgarian Grigor Dimitrov, who secured a spot in the quarterfinals with a 6-3, 3-6, 6-2, 6-4 victory over Spaniard Roberto Bautista Agut.
The 22-year-old Dimitrov will make his first-ever appearance in a Grand Slam quarterfinal in his 14th try, while Nadal will be appearing in his seventh quarter at the Aussie Open alone.
Meanwhile, the fourth-seeded three-time Aussie runner-up Murray reached his fifth straight major quarterfinal by getting past French lucky loser Stephane Robert 6-1, 6-2, 6-7 (6-8), 6-2 at Hisense Arena on Day 8 of this Oz fortnight.
Murray wasted four match points in the third set and smashed his racquet after the third-set tiebreak before advancing.
"He's a fun player to watch, but not a fun player to play," Murray said of Robert, who can baffle with an array of drop shots and groundstrokes.
Murray, who was last year's Aussie runner-up to Novak Djokovic, will battle Federer in a quarterfinal on Wednesday.
The sixth-seeded Federer avenged a quarterfinal loss at the hands of Frenchman Jo-Wilfried Tsonga here a year ago by unleashing his full arsenal of shots in dismissing the 10th seed 6-3, 7-5, 6-4. The super Swiss was not broken on Day 8, while Tsonga was broken three times by the 17-time Grand Slam king.
The former world No. 1 Federer tied Jimmy Connors' record by reaching his 41st Grand Slam quarterfinal. It's also the 11th straight year the Swiss icon has reached the quarters at Melbourne Park.
Tsonga was the 2008 Aussie Open runner-up to Djokovic.
The quarterfinals will commence Tuesday, as a second-seeded Djokovic takes on eighth-seeded Swiss Stanislas Wawrinka and third-seeded David Ferrer meets seventh-seeded Tomas Berdych.
The former No. 1 Djokovic is a dominant 15-2 lifetime against Wawrinka, including a fourth-round win here a year ago. The Serbian star also topped the Swiss in a U.S. Open semifinal last season.
Last year's French Open runner-up Ferrer is 7-4 lifetime versus the former Wimbledon finalist Berdych.
Djokovic has won his last 25 matches at the Aussie Open, where he's the three- time reigning champion and has captured four of the last six titles Down Under.