Frances Tiafoe of the United States defeated Andrey Rublev in straight sets to power into the semi-finals of the US Open on Wednesday.
Tiafoe, aiming to become the first African-American man to win the US Open since Arthur Ashe in 1968, put on a scintillating performance to defeat Russian ninth seed Rublev 7-6 (7/3), 7-6 (7/0), 6-4 in 2hr 36min.
It was another superb giant-killing performance from the 24-year-old Tiafoe, who eliminated Spanish legend Rafael Nadal in the fourth round on Monday.
Tiafoe, seeded 22nd, will face either Spanish third seed Carlos Alcaraz or Jannik Sinner in his first career Grand Slam semi-final appearance on Friday.
"Man this is wild, this is crazy," Tiafoe said after his victory at the Arthur Ashe Stadium.
"Having the biggest win of my life and coming out and getting another big win. Andrey's a hell of a player, so to back it up is huge growth. Tough to turn the page but I did and now I'm in the semis."
Tiafoe, the son of immigrants from Sierra Leone who began playing tennis as a four-year-old when his father worked as a live-in caretaker at a tennis facility in Maryland, said he had drawn inspiration from the raucous home crowd on Arthur Ashe.
"I always find a way somehow on this court," he told fans during an on-court interview.
"Let's enjoy this one – we've got two more guys, two more."
Tiafoe's victory was founded on a rock-solid service game and a mastery of the key moments.
The American hammered down 18 aces and was never broken once against Rublev, who was aiming to reach his first Grand Slam semi-final after five previous quarter-final exits.
Crucially, Rublev was unable to take any of four break points that came his way during a high-quality contest settled by the finest of margins.
The Russian 24-year-old had a break point at 6-5 in the first set but was unable to convert as Tiafoe battled back to hold.
Tiafoe then showed the greater composure in the tie-break to seal it with an ace for a one-set lead.
The second set played out in almost identical fashion, going to a tie-break after neither man could find a break of serve.
But once again it was Tiafoe who rose to the moment. Back-to-back aces took him into a 5-0 lead before a beautiful sliced backhand gave him six points for a two-set lead. He duly converted the first to leave Rublev with a mountain to climb.
The Russian did well to hold serve in the third game of the third set, recovering from 15-40 down.
Yet Tiafoe grabbed a break for a crucial 4-3 lead soon afterwards that left Rublev overcome with emotion, appearing to sob into his towel.
Tiafoe held off two break points in the next game and took a 5-3 lead with his 17th ace before closing out the win.