Third seed Novak Djokovic stunned world number one and defending champion Roger Federer to reach the Australian Open final with a 7-5 6-3 7-6 (7-5) victory.
To widespread disbelief Federer could not find a way into the match
Federer earned the first break to serve for the set but a series of errors saw him lose four games in succession.
He was broken twice in the next set and though he clawed one back he was still unable to exert his usual dominance.
The third was closer but Federer could not find consistency and Djokovic triumphed in an hour and 57 minutes.
Sunday's final between Djokovic and unseeded French sensation Jo-Wilfried Tsonga will be the first time since the 2005 Australian Open that neither Federer nor world number two Rafael Nadal will feature in the finale of a Grand Slam.
Federer was bidding for his 11th consecutive Grand Slam final and victory in the final would have put him one behind Pete Sampras' record of 13 major titles.
Following Jo-Wilfried Tsonga's demolition of Nadal on Thursday, few could have predicted a similar fate for the assured Federer, especially when he served for the first set at 5-4.
Djokovic took advantage of the unexpected Federer lapses
But the Swiss star produced some uncustomary unforced errors and did not win another game as the opener went to Djokovic in 45 minutes.
Worse was soon to follow for Federer, when his Serbian opponent somehow reached his volley and threaded a backhand down the line from an acute angle to break in the fourth game.
Inexplicably, Federer was broken again and found himself staring at a 5-1 deficit.
Having retrieved one of the breaks, the top seed saved one set point with a trademark thumping forehand into the corner but Djokovic was not to be denied and clinched the second set in 40 minutes with an ace.
Federer had not been 2-0 down in a five-set match since Miami in 2005 when he hit back to win, and his followers hoped he could manage the same miraculous resurgence.
It seemed as if the first cracks had begun to appear in his opponent when Federer created three breaks points in Djokovic opening service game of the set.
But the 20-year-old from Belgrade rallied, sealing the game with an ace, and then carved out two break point chances of his own in the next.
He was unable to take those and the third set continued to go with serve.
Federer forged set point on two occasions and though they were saved by Djokovic, the world number one looked better in the early stages of the tie-break.
But, summing up the pattern of the match, his best form eluded him and he bowed out.
"I am just very amazed I coped with the pressure today," Djokovic said.
"In the most important moments, I played my best tennis.
"It's just amazing, indescribable, to beat the number one player in the world, one of the best players this sport has ever had, in straight sets."
Reflecting on a rare semi-final defeat Federer said: "You can't always play your best. There is no doubt I have played better before.
"I couldn't come up with the passing shot when I needed to but he covered the court well."