Rafael Nadal appeared to be on the brink of repeating one of his most famous victories here, only to suffer a defeat which casts further doubt on whether he can ever reclaim his former glories.
When Nadal won his only Australian Open title in 2009, he did so after beating Fernando Verdasco in the semi-final in the second longest match in the tournament's history, a five-set epic that lasted five and a quarter hours.
The two Spanish left-handers went the distance again yesterday, but this time it was Verdasco who came out on top, winning 7-6 4-6 3-6 7-6 6-2 after a marathon battle that lasted four hours and 40 minutes. Verdasco, aged 32, had lost all but two of their previous 16 meetings.
Nadal, who let slip a two-sets-to-one lead, went 2-0 up in the decider before Verdasco went for broke, hitting some huge forehand winners.
One of the best came on match point, when the World No.45 cracked a huge return of serve that flew beyond Nadal's reach.
Despite enduring his worst season in Grand Slam play since 2004, Nadal had appeared to be returning to form in the latter stages of 2015 and talked here about his "happy feelings" as he went into the year's opening Grand Slam event.
"The match is obviously a tough one for me to lose," Nadal said afterwards. "Last year, I arrived here playing badly and feeling I was not ready for the tournament. This year was a completely different story. I have been playing and practising great.
"It's tough when you work so much and arrive at a very important event and you're going out too early.
"It's tough but at the same time I know I did everything that I could to be ready. This was not my day. Let's keep going. That's the only thing."
In his pomp, Nadal's forehand was the most destructive shot in the game but he was out-powered by Verdasco, who hit an incredible 90 winners to his opponent's 37.
Nadal has been working on playing further forward and asserting more authority in matches but he was unable to dictate as much as he would have liked.
"I wasn't able to do much damage with my forehand, so I was hitting forehands and he was able to keep hitting winners," Nadal said.
"That cannot happen when I am hitting my forehand. Usually if my opponent wants to hit a winner, he is going to have to take a big risk. In my opinion, that was not the case here."
Verdasco will now play Israel's Dudi Sela in round two and may feel a sense of justice after he lost a classic five-set contest with Nadal in the 2009 Australian Open semi-finals.
Verdasco said: "I don't know how many times I have watched that match, maybe 10 times.
"Still now they come to me telling me how good I played seven years ago. I'm like, you know I didn't play again after that? Even last night they told me at the hotel.
"People have came to me and told me about that match so many times."
Meanwhile, the Lleyton Hewitt farewell show goes on with the retiring former champion extending his storied Australian Open career with a stirring first-round win over countryman James Duckworth.
A who's who of Australian tennis, including Hewitt's past four Davis Cup captains - John Newcombe, John Fitzgerald, Pat Rafter and Wally Masur - were all on hand at the Rod Laver Arena to see the former World No.1 in action for possibly the last time.
Once the five-set king of tennis, Hewitt has lost his past six matches that have gone the distance and even his most loyal of fan must have been edgy when Duckworth led 4-2 in the third set.
But, not for the first time, the baseline warrior rallied back to win four straight games and raise the roof after clinching his first Grand Slam win since last year's Open with a trademark topspin lob on match point.
"This is what I'm going to miss most - this adrenaline buzz of coming out here," Hewitt said. "Hearing Craig Willis announce you from Australia and the whole crowd erupts. It doesn't get any better than that."