Spanish second seed Nadal was forced to dig deep to beat Tomas Berdych, battling back from a set down in the evening match on Rod Laver Arena to subdue his Czech opponent 6-7 (5/7), 7-6 (8/6), 6-4, 6-3 in 4hr 16min.

In sharp contrast, Swiss maestro Federer, chasing his fifth title in Melbourne, barely broke sweat as he dismantled his Argentine opponent 6-4, 6-3, 6-2 in a rematch of the 2009 US Open final won by del Potro.

It means Federer and Nadal will clash in Melbourne again on Thursday, three years after the Spaniard, who leads their head-to-heads 17-9, reduced the Swiss to tears with a five-set win in 2009's epic Australian Open final.

Federer, the third seed, brought up his 1,000th tour-level match with his win, which he described as a "big milestone".

"It's nice to win this one. I mean, eventually I will forget which was one was my 1,000th match and someone will remind me again," said Federer, 30.

"I do not remember my 500, and that was the US Open final against Agassi (2005). No bigger matches than those ones."

Federer started his match against del Potro in ominous fashion, unveiling his full repertoire of strokes and breaking del Potro at his first opportunity.

The tall del Potro, seeded 11th, settled and forced a break of his own in the seventh game, but a double-fault cost him the opener.

An exquisite backhand down the line gave Federer another break and a 3-1 lead in the second set, and he moved two sets clear after a tough ninth game in which he was forced to save four break points.