Even though it was a semi-final the anticipation for a classic from Roger Federer and Rafael Nadal is probably bigger than any other tennis clash. (All AFP and AP Images)
Four-time Australian Open champion Federer was off the blocks quickly. He held his serve to love and broke the Spaniard at his first opportunity with a devastating cross-court backhand with Nadal struggling to gain a foothold.
Nadal broke back but third seed Federer raised his game again after his mid-set wobble and he took the tie-break when Nadal went long.
The players swapped service breaks at the start of the second set but the turning point came when Nadal broke Federer in the sixth game to move ahead 4-2. The World No. 2 then went on to win the next two games to take the set 6-2.
Kim Clijsters (2nd L, last row) was in the stands to watch the two stalwarts fight it out with each other.
Federer battled hard to break Nadal in game seven of the third set but the Spaniard broke back immediately to level things up and Nadal went on to take the tie-break on his sixth set point.
A tense fourth set went with serve with Nadal looking mentally stronger, continuing to chase down balls from seemingly impossible situations.
But the Spaniard still had to fight hard to serve out for victory, saving two Federer break points, including an astonishing retrieval onto the baseline which the Swiss then hit wide.
Nadal won 6-7 (5/7), 6-2, 7-6 (7/5), 6-4 to prolong the agony for his greatest rival, who has now lost eight times to the Spaniard in 10 grand slam meetings and has not beaten him in the majors since Wimbledon 2007.
The match was the 10th grand slam encounter between Nadal and Federer, putting them equal with Ivan Lendl and John McEnroe for most matches played at majors.
In the women's semifinals, Maria Sharapova overcame some poor serving to avenge her 2011 Wimbledon final loss to Petra Kvitova with a 6-2, 3-6, 6-4 win.
Sharapova dominated the first set and Kvitova the second, with the pair evenly matched in the third until Kvitova faltered at 4-5 to lose her serve.
Sharapova set up a final against Victoria Azarenka at Rod Laver Arena, a match that will also decide the No. 1 ranking.
In the other semi-final, Azarenka was in tears as she reached her first Grand Slam final after defeating defending champion Kim Clijsters 6-4, 1-6, 6-3.
The Belarusian won the opener in 49 minutes but Clijsters rallied in the second set as she cut down her error-rate and forced Azarenka into a series of long rallies.
In the final set, Azarenka broke Clijsters to go up 5-3 and then held her nerve for a memorable victory.