New York - Defending champion Novak Djokovic stormed into a sixth successive US Open semi-final on Thursday with a breathtaking 6-2, 7-6 (7/3), 6-4 demolition of 2009 winner Juan Martin Del Potro.
The second-seeded Serb is bidding to win a sixth Grand Slam title and is now the comfortable tournament favourite following the elimination of world number one Roger Federer.
He goes on to face Spanish fourth seed David Ferrer, who defeated Serb eighth seed Janko Tipsarevic 6-3, 6-7 (5/7), 2-6, 6-3, 7-6 (7/4), for a place in Sunday's final.
Saturday's other semi-final sees third seed Andy Murray face Tomas Berdych of the Czech Republic.
Australian Open champion Djokovic took his career record over Argentina's Del Potro, who beat him for Olympic bronze last month, to 6-2 as he marched into a 10th successive major semi-final.
"I love playing night sessions but this was much closer than the scoreline suggests," said Djokovic, who finished Thursday's tie with 43 winners.
"Juan Martin is a great player and I was lucky in the second set. There were some incredible points and rallies. He came up with some great forehands but he is a big guy and I wanted to keep him moving from side to side."
Djokovic defends an 8-5 record against Ferrer.
"It will be another big battle. David has been one of the most consistent players over the last six, seven years but few people ever talk about him. I will have to be very competitive," said the champion.
Del Potro admitted Djokovic had out-played him.
"He is playing better and better. I had the chance to take the second set but he played the important points well," said the Argentine. "He was just too much for me."
Djokovic spent five and a half hours fewer than Del Potro reaching the quarter-finals, dropping just 14 games in his first three rounds before seeing Stanislas Wawrinka retire from their fourth-round clash in the third set.
He certainly looked the fresher at the start on a humid Thursday night on Arthur Ashe Stadium, racing through the first set with breaks in the fourth and eighth games with the big Argentine winning just five points on the Serb serve.
But seventh seed Del Potro, who sent Andy Roddick into retirement in the previous round, soon rallied, winning 10 straight points on his way to a 2-0 lead in the second set.
He served for the set at 5-4 but that was the cue for Djokovic to light up the night with his deadly returning power and iron-willed defence.
A gruelling 26-shot rally gave the world number two break point, which he converted to 5-5 despite spending the entire point being pushed from side to side.
In an 18-minute 12th game, Del Potro saved three set points before he wilted in the tie-breaker.
He slipped to 6-3 down after a gruelling, fruitless rally, ending it slumped over the net through exhaustion.
Djokovic then claimed the set, which had taken 84 minutes to complete, with a blistering down-the-line backhand.
Del Potro, seeking to reach only his second semi-final at a major, had never come back from two sets to love down in his career and he was soon 2-0 down in the third set.
The 23-year-old Argentine fought off two break points in the fifth game but Djokovic claimed victory when Del Potro buried a drive into the net.
Results on Thursday from the 11th day of the US Open (x denotes seeding):
David Ferrer (ESP x4) bt Janko Tipsarevic (SRB x8) 6-3, 6-7 (5/7), 2-6, 6-3, 7-6 (7/4)
Novak Djokovic (SRB x2) bt Juan Martin Del Potro (ARG x7) 6-2, 7-6 (7/3), 6-4
Leander Paes/Radek Stepanek (IND/CZE x5) bt Marcel Granollers/Marc Lopez (ESP x6) 6-6 retired
Bob Bryan/Mike Bryan (USA x2) bt Aisam-Ul-Haq Qureshi/Jean-Julien Rojer (PAK/NED x9) 6-3, 6-4
Sara Errani/Roberta Vinci (ITA x2) bt Nuria Llagostera Vives/Maria Jose Martinez Sanchez (ESP x8) 6-3, 6-2
Andrea Hlavackova/Lucie Hradecka (CZE x3) bt Hsieh Su-Wei/Anabel Medina Garrigues (TPE/ESP x16) 7-6 (7/2), 6-4
Ekaterina Makarova/Bruno Soares (RUS/BRA) bt Kveta Peschke/Marcin Matkowski (CZE/POL x4) 6-7 (8/10), 6-1, 12-10