Dark horse Kevin Anderson advances to US Open final
Anderson, No. 32 in the world, becomes the lowest-ranked player to reach the final in New York since the launch of the ATP rankings in 1973.
The 31-year-old will also be playing in his first Grand Slam final, where his opponent will be the winner of the other semifinal between Spain's Rafael Nadal and Argentine Juan Martin del Potro.
Anderson, who stands 2.03 meters (6 ft, 8 in) tall, hit 22 aces against the 12th-seeded Carreño Busta.
Both semi-finalists benefited from a depleted bottom half of the draw, which opened up when injured Scottish world No. 2 Andy Murray withdrew from the tournament prior to his first match and sixth-ranked German Alexander Zverev was upset in the second round.
Other top men's singles players also were forced to miss tennis' most prestigious hard-court event due to injuries: Serbian great Novak Djokovic, Canada's Milos Raonic, Swiss defending champion Stan Wawrinka and Japan's Kei Nishikori.
"It's been a long road. We've been privileged to play in these tournaments against some of the game's great players. It was nice for some of them to give us the opportunity to do this (by their absence). It's why we worked so hard. It was an unbelievably tough match for both of us. I really had to dig deep there. I'm just over the moon. I've given myself one more shot," Anderson said after the victory.
"Last year, I was told I probably needed surgery on my hip, but here I am just nine months later. This means the absolute world to me," he said.