MELBOURNE (Reuters) -Germany's Alexander Zverev stunned second seed Carlos Alcaraz to reach the Australian Open semi-finals as a sublime display of serving took him to a 6-1 6-3 6-7(2) 6-4 victory on Wednesday.
Zverev landed 94 of 111 first serves throughout the three hour, five minute contest and even when Alcaraz threatened a remarkable comeback from 2-5 down in the third set the German showed great composure to seal victory.
In his seventh Grand Slam semi-final, Zverev will need similar accuracy as he takes on Russian Daniil Medvedev, a player he lost to on five of their last six meetings.
Alcaraz was comprehensively outplayed for almost three sets but belatedly found his A-game to win a third-set tiebreak with a mind-boggling flurry of outrageous winners.
Sixth seed Zverev was suffering from blood blisters on his feet during a riveting fourth set but held firm under a withering Alcaraz attack.
His metronomic serving and bullet-proof backhand then got him over the winning line against a top-five opponent for the first time at a Grand Slam.
"He's been number one and number two in the world and won two Grand Slams so when you're up 6-1 6-3 5-2 against a player like Carlos you start (over) thinking because we are all human," Zverev, who landed 85% of his first serves, said on court.
"Your brain starts going and it's not always helpful but I'm happy I got there in the end. I fought back pretty well in the fourth set and didn't let go."
For Alcaraz it was a sobering defeat by a player against whom he has now lost five times.
"I'm sad with my level today, because I have been playing good tennis," he said. "But in general, I think I did a pretty good tournament."
Zverev had spent nearly 14 hours on court to reach the quarter-finals while 20-year-old Alcaraz had roared through the draw and was firm favourite for Wednesday's clash.
But the Spaniard was caught cold as Zverev came out swinging, dropping only two points on serve as he raced through the opening set with clinical ease.
Zverev failed to land only four first serves in the opening two sets and two breaks of the Alcaraz delivery in the second set enabled him to seize complete control.
A subdued Alcaraz looked at a loss to know what to do but when Zverev served for the match at 5-3 something clicked and he broke serve for the first time to stay alive -- a huge smile spreading across his face as he sat down at the change of ends.
PLAYING FREELY
Suddenly playing freely, a re-energised Alcaraz produced four successive winners from 0-2 down in the tiebreak as he reeled off seven points to take the match past midnight.
Whipping the late-night Rod Laver Arena crowd into a frenzy, Alcaraz looked favourite to take the match into a decider as Zverev began to hobble at times as Alcaraz began to dictate with his huge power and deft drop shots.
But Zverev showed great resilience to hold serve in a pulsating eighth game which Australian maverick Nick Kyrgios, co-commentating for Eurosport, described as "insanity".
Zverev summoned one final effort at 4-4 and some stunning hitting off his trusty backhand wing gave him the break and 50 minutes after first serving for the match he managed to complete a remarkable victory.
He now has a day to patch himself up for his second Australian Open semi-final, having been beaten by Dominic Thiem at the same stage four years ago.
"I have a lot of blood under my toenails," he said. "But I would rather feel the pain and be in the semis than be at home watching on TV. I'm ready to go again."
(Reporting by Martyn HermanEditing by Christian Radnedge)