Melbourne - Marin Cilic became the first Croatian to reach the semi-finals of the Australian Open with a gripping five-set victory over American Andy Roddick on Tuesday.
Cilic, at 21 the youngest of the eight quarter-finalists, wore down the seventh seeded Roddick, 7-6 (7/4), 6-3, 3-6, 2-6, 6-3 in three hours 50 minutes on Rod Laver Arena.
His reward is a semi-final against either defending champion Rafael Nadal of British fifth seed Andy Murray, who play later Tuesday.
It was another test of endurance for the 14th seeded Cilic, who has spent the longest time on court of all the remaining players in the draw at 18 hours eight minutes for his five matches.
It was the marathon man's third five-set match of the tournament.
Cilic looked as if his challenge was fading when Roddick fought back to level at two sets all after the Croatian had claimed the opening two sets.
But he found his second wind in the gruelling deciding set to finish off Roddick, who was bidding for his fifth semi-final appearance at the Australian Open.
Cilic remains unbeaten this year at 10-0 after defending his title at Chennai on his way to Australia.
It was his second consecutive quarter-final appearance at a Grand Slam after losing to eventual champion Juan Martin del Potro at last year's US Open.
Yet again it was more heartbreak for Roddick as he fell short in his bid to add to his sole Grand Slam title from the 2003 US Open.
Roddick is the last American male Grand Slam champion, the longest major title drought for the proud tennis nation.
He has a losing five-set career record of 12-15, while Cilic is 8-5.
The young Croat prevailed even though he struggled on serve with his first serve percentage down to 50 percent, but he out-aced the power-serving Roddick 20 to 15.
He broke Roddick's serve five times and dropped his six times.
Results from day nine of the Australian Open at Melbourne Park on Tuesday (x denotes seeding):
Men's singles
Quarter-finals
Marin Cilic (CRO x14) bt Andy Roddick (USA x7) 7-6 (7/4), 6-3, 3-6, 2-6, 6-3
Women's singles
Quarter-finals
Justine Henin (BEL) bt Nadia Petrova (RUS x19) 7-6 (7/3), 7-5
Zheng Jie (CHN) bt Maria Kirilenko (RUS) 6-1, 6-3