Rafael Nadal left himself vulnerable at the Australian Open, but it still took a special performance to send him packing in Melbourne.
Marin Cilic's 83 winners and an injury eventually combined to send Nadal out, the Spaniard retiring when trailing 3-6 6-3 6-7 (5-7) 6-2 2-0.
With his plan in place, Cilic executed well enough for long enough against Nadal.
Taking on a player he last beat in 2009 - the only time he had tasted success in the match-up - Cilic had the contest on his racquet almost from the outset.
His serve stood up to the test and his aggression paid off after a gruelling three hours and 47 minutes in cool conditions on Rod Laver Arena on Tuesday.
Nadal, so often the man who pushes his opponents to the brink and beyond, was the one left limping - due to a suspected leg injury - in a quarter-final exit at Melbourne Park.
Cilic targeted the Spanish superstar's backhand from the outset and he attacked the net regularly - winning 35 of 47 points from that position.
He was brave and the high-risk, high-reward strategy worked, although he had to come from two sets to one down.
Serving from the deuce court, Cilic repeatedly went to Nadal's backhand - often taking pace off his serve - to push the 16-time grand slam champion so wide it was often a matter of simple volleys to win easy points.
Summing up Cilic's approach was his set-point save during the third set, one which he would nonetheless lose in a tie-break.
Despite the tricky position, he attacked bravely and powerfully with his groundstrokes - particularly his forehand - to initially save the set, one he should have won.
But Cilic was then rewarded for being proactive, taking the fourth set and breaking in the fifth before Nadal retired.
Nadal finished with just 39 winners and his lack of aggression hurt, as it showed signs of doing against Diego Schwartzman in the fourth round.
A men's draw that had looked predictable, with another Nadal versus Roger Federer final likely, was broken open in the space of two days.
Novak Djokovic fell at the hands of Hyeon Chung, Kyle Edmund stunned Grigor Dimitrov and Cilic overcame Nadal.
Not only was the prospect of a Federer-Nadal final repeat wiped away, so was the possibility of another epic last-four clash against Dimitrov for the Spaniard.
But Nadal left the match on the racquet of his opponent and Cilic, the 2014 US Open champion, took the opportunity in convincing fashion.