The second-seeded Nadal snuck past seventh-seeded Czech Tomas Berdych in four sets, while a third-seeded Federer whipped 11th-seeded Argentine slugger Juan Martin del Potro in straights in a rematch of the 2009 U.S. Open final, which was won by the towering del Potro. Nadal beat Berdych in the 2010 Wimbledon championship match.
The 30-year-old Federer played in his 1,000th ATP-level match on Tuesday and secured a berth in his 30th Grand Slam semifinal.
"It's a lot of matches and a lot tennis," Federer said. "Either I have been around for a long time or I'm extremely fit. You decide which way you want to describe it. But I'm happy."
The 10-time major champion and reigning French Open titlist Nadal was tested mightily in a 6-7 (5-7), 7-6 (8-6), 6-4, 6-3 victory over Berdych at Rod Laver Arena, where the legendary Aussie Laver was on hand to watch on Day 9. The 16- time Grand Slam titlist Federer dismantled del Potro 6-4, 6-3, 6-2 earlier Tuesday in quarterfinal action at Laver.
Nadal needed a whopping 4 hours, 16 minutes to stave off a game Berdych, who finally succumbed on Nadal's first match point by framing one final forehand into the court, as the mighty Spaniard broke to close out the quality affair.
The fiery Nadal saved four set points in the opening stanza, including one with an incredible cross-court passing shot on the 29th point of a rally. But Berdych would win the ensuing tiebreak.
Nadal then snuck out the second-set tiebreak on his way to taking the last three sets of the match, as he simply got stronger at the bout wore one.
"Happy with how I finished match physically, I was able to keep running with high intensity," Nadal said.
Berdych fired 17 aces, but also piled up 56 unforced errors and had his serve broken five times, compared to only two breaks he tallied against the Spanish strongman, who beat the big Czech for a 10th straight time.
The four-time Aussie Open champion Federer, meanwhile, handled del Potro in just 1 hour, 59 minutes, as the super Swiss recorded 38 winners to send the Argentine home after he reached his first Grand Slam quarterfinal since the '09 U.S. Open.
"We have played some big matches against each other, so just knowing how well he's been playing as of late, I was just hoping that I would get off a good start," Federer said. "I was able to mix it up well and control the ball, and right away sort of felt confident."
Federer, who hasn't won a Grand Slam event since titling here in Melbourne two years ago, has yet to drop a set at this latest Aussie fortnight. He'll now appear in his ninth straight Aussie semi.
The 25-year-old Nadal and Federer will meet for a 27th time, with the Spaniard leading the all-time series 17-9. Nadal is 7-2 in their Grand Slam meetings, including wins in their last four matchups. The two stalwarts have met in a record eight major finals, with Nadal winning six of them. They are in the same half of the draw at a major for the first time since 2005.
Nadal topped Federer in five sets in the 2009 Aussie Open finale.
The other quarterfinals will be staged on Wednesday, as current world No. 1 Novak Djokovic will face fifth-seeded Spaniard David Ferrer and fourth-seeded Andy Murray will take on 24th-seeded Japanese Kei Nishikori.
Djokovic is 6-5 lifetime against Ferrer, who titled in Auckland two weeks ago and is already a perfect 8-0 this season.
The high-flying Djokovic beat Murray in last year's Aussie final to capture his second title here in four years. The four-time major champion is also the reigning Wimbledon and U.S. Open titlist.
Djokovic has won 36 of his last 38 Grand Slam matches and is seeking a third straight major title. A title this week would put him in select company, as only four players -- Laver, Pete Sampras, Federer and Nadal -- have captured three straight Grand Slam championships in the Open Era (since 1968).
Murray, who titled in Brisbane three weeks ago, is a three-time major runner- up, including a loss to Federer in the 2010 Aussie Open finale.
Nishikori is the first Japanese man to reach the quarterfinals at a Grand Slam event since Shuzo Matsuoka in 1995 (Wimbledon) and he's also the first Japanese man in 80 years to advance to the Aussie Open quarters, since Ryosuki Nunoi and Jiro Satoh turned the trick way back in 1932.
Djokovic, Nadal and Federer have combined to win seven of the last eight Aussie Open titles.