Britain's Andy Murray ended Alexandr Dolgopolov's brilliant debut at Melbourne Park after he slayed the giant-killing Ukrainian 7-5 6-3 6-7 6-3 with an impeccable defensive game to ease into the semi-finals of the Australian Open.
Up two sets and a break in the third, the spring-heeled Scot appeared to be cruising to victory, but was stunned when Dolgopolov broke back and prevailed in a tense battle of nerves to win the third-set tiebreaker 7-3.
The resurgence was to prove fleeting as Dolgopolov, the world number 46 who beat Jo-Wilfried Tsonga and Robin Soderling in his previous two matches, self-destructed early in the fourth set, and fell back 4-0 to allow Murray to calmly serve out the 186-minute match on a chilly summer's day at Rod Laver Arena.
The victory ensured fifth seed Murray entered his second successive semi-final at Melbourne Park as he seeks to end Britain's 75-year wait for a men's grand slam champion.
The Briton will play the winner of the match between David Ferrer and Rafael Nadal for a place in the final.
After Murray avoided a nerve- jangling deciding set, he will need to consistently rediscover his best form if he is to come through Friday's semi-final encounter and return to the final 12 months after defeat to Roger Federer, although neither Spaniard is likely to provide such an unorthodox opposition as Dolgopolov.
The British number one was the last man to beat Nadal at a grand slam event after seeing him off in the quarter-finals in Melbourne last year.
Nadal is hoping to become the first man since Rod Laver in 1969 to hold all four major titles simultaneously.
"Every point against him (Dolgopolov) is different, he hits the ball differently to everyone else, it's tough to explain," said Murray. "I struggled with my rhythm early on and he came back, but I thought I did well enough."