New York - South Africa's Kevin Anderson has reached the US Open semi-finals after beating America's Sam Querrey 7-6 (7/5), 6-7 (9/11), 6-3, 7-6 (9/7) in their quarter-final clash.
It will be Anderson's first appearance in the last four of a Grand Slam, improving on his quarter-final run at the US Open in 2015.
The last South African to reach the semi-finals of a Grand Slam was Wayne Ferreira at the 2003 Australian Open.
Anderson will also have the chance to become the first South African to make the US Open final since Cliff Drysdale in 1965, when the tournament was called the US National Championships.
The 28th-seeded Anderson is appearing in his 34th major tournament.
His victory against the 17th-seeded Querrey concluded a little before 02:00 (08:00 SA time) on Wednesday in front of a sparse crowd at Arthur Ashe Stadium - and it did not come easily.
"Getting through - it just feels absolutely fantastic," Anderson said.
The 6-foot-8 (2.03m) Anderson finished with 22 aces; the 6-foot-6 (1.98m) Querrey hit 20.
Anderson trailed 5-2 in the opening tie-breaker before collecting the next five points to claim it. He fought back from a 6-1 deficit in the second tie-breaker to move within a point of winning it himself at 8-7, before eventually succumbing on Querrey's eighth set point.
"That," Anderson said, "was really tough."
The third set was more straightforward with Anderson breaking to go ahead 4-2, then serving it out, closing with a down-the-line forehand winner. But there was more drama in the fourth, when Querrey fought off a match point at 6-5, then held a set point at 7-6 with a chance to send it to a fifth.
But Querrey wouldn't win another point, with Anderson reeling off the last three to end the match after nearly three-and-a-half hours.
Querrey was attempting to become the first American man to reach the final four at Flushing Meadows since Andy Roddick was the runner-up in 2006.
Querrey, a 29-year-old from California, had never been a semi-finalist at a major until his 42nd appearance, at Wimbledon in July. That set a record for most attempts by a man before getting that far in the Open era.
In Friday's semi-finals, Anderson will take on 12th-seeded Pablo Carreno Busta of Spain. The winner of that match will reach his first Grand Slam final.
Carreno Busta advanced with a 6-4, 6-4, 6-2 victory over No 29 Diego Schwartzman of Argentina.
Results from day 9 of the US Open (x denotes seeding):
Kevin Anderson (RSA x28) bt Sam Querrey (USA x17) 7-6 (7/5), 6-7 (9/11), 6-3, 7-6 (9/7)
Pablo Carreno-Busta (ESP x12) bt Diego Schwartzman (ARG x29) 6-4, 6-4, 6-2
Venus Williams (USA x9) bt Petra Kvitova (CZE x13) 6-3, 3-6, 7-6 (7/2)
Sloane Stephens (USA) bt Anastasija Sevastova (LAT x16) 6-3, 3-6, 7-6 (7/4)