American men's tennis slumped to an historic Grand Slam low on a sweltering Sunday at the US Open as Novak Djokovic and Andy Murray remained on course for a blockbuster semi-final.
Wildcard Tim Smyczek was America's last hope of avoiding the embarrassment of not having a man in the fourth round of the country's own Grand Slam for the first time in the Open era.
But Spain's Marcel Granollers delivered the executioner's blow when he beat 109th-ranked Smyczek 6-4, 4-6, 0-6, 6-3, 7-5 to reach the last 16 and condemn the US to humiliation in a sport they once dominated.
In an historic flop, no US man reached the fourth round of any of the year's four majors.
"I really wanted to win for you guys," said Smyczek. "I just came up a little short."
The US Open wipeout came on the heels of no US man reaching the third round at Wimbledon for the first time since 1912 and it leaves Andy Roddick as their most recent Grand Slam champion when he won in New York in 2003.
Djokovic, the reigning Australian Open champion and the US Open titlist in 2011, brushed aside world number 95 Joao Sousa, the first Portuguese man to make the third round, 6-0, 6-2, 6-2 to make the last 16.
Third-seeded defending champion Murray eased past Germany's world number 49 Florian Mayer, 7-6 (7/2), 6-2, 6-2 while 2001 champion Lleyton Hewitt maintained his dream run with a 6-3, 7-6 (7/5), 6-1 win over Russia's Evgeny Donskoy.
Djokovic, the 2011 champion and bidding to reach the final for a fourth year in succession, next faces Granollers, who he has beaten in their only previous meeting, for a place in the quarter-finals.
"I just do my job, win in straight sets, and spend as little time on court as possible," said Djokovic after unleashing 34 winners past the hapless Sousa.
Murray, who ended his country's 76-year wait for a Grand Slam men's champion when he won his maiden major title in New York last year, eased past Germany's world number 49 Florian Mayer, 7-6 (7/2), 6-2, 6-2.
His win was built on an impressive 42 winners and seven aces.
"I think I need to start my matches quicker than I have been doing. I am not that fast out of the blocks," said the 26-year-old. "But once I got going I was striking the ball cleanly."
Murray, the reigning Olympic and Wimbledon champion, will next face Uzbekistan's world number 65 Denis Istomin, who put out Italian 20th seed Andreas Seppi, 6-3, 6-4, 2-6, 3-6, 6-1.
Istomin will be playing in the last 16 in New York for the first time after ending Seppi's perfect streak of seven five-set wins in 2013. Two of those came against him at the Australian Open and Wimbledon.
Murray defeated Istomin in their only match in the quarter-finals at Brisbane in January this year.
Hewitt reached the fourth round of a Grand Slam for the 30th time with a 6-3, 7-6 (7/5), 6-1 win over Russia's Evgeny Donskoy.
The former world number one, who knocked out sixth seed and 2009 winner Juan Martin Del Potro in the second round, last reached the fourth round in 2006, when he went on to the quarter-finals.
"It's always great to come back to New York where it all started for me -- I won the doubles in 2000 and singles in 2001. I have played some of my best tennis here," said Hewitt, who claimed victory on a third match point.
The 32-year-old world number 66 will next face Russia's 21st seed Mikhail Youzhny, twice a semi-finalist, who put out German 12th seed Tommy Haas 6-3, 6-2, 2-6, 6-3.
Haas at 35 was the oldest man in the draw, but his challenge was hobbled by a right foot injury. Hewitt has a 5-1 career lead over Youzhny.
Fifth seed Tomas Berdych of the Czech Republic and Swiss ninth seed Stanislas Wawrinka will clash for a spot in the quarter-finals.
Berdych, who defeated five-time winner Roger Federer on his way to the semi-finals last year, eased past French 31st seed Julien Benneteau, 6-0, 6-3, 6-2.
Wawrinka, a quarter-finalist in 2010, got past unseeded Cypriot Marcos Baghdatis, the former world number eight but now down at 53 in the world, 6-3, 6-2, 6-7 (1/7), 7-6 (9/7).