The South African finally drew first blood as Carreno Busta started to lose confidence in himself, with more unforced errors coming off his racquet.
If you were to look at pre-tournament form as a guide, then Carreno Busta doesn't even rate a mention with early exits in Montreal and Cincinnati.
A 20th ace of the match from Anderson wrapped up the third, with his command furthered in the fourth as he moved within three games of victory when Carreno Busta went wide with a forehand.
And after it cost Lucie Safarova the point, she called out her friend on social media for a lack of sportsmanship after her team lost. I won a lot of points here to continue my way to the Masters.
Serena Williams might be on a leave of absence from the tennis tour, but she is definitely paying attention to the U.S. Open. The crowd at Arthur Ashe, who nearly expected Querrey to advance to his first grand slam final were left stunned as the South African put in a pearling performance.
When Anderson walks on to the court in a major Grand Slam match with the South African flag behind his name, it should be enough reason for us to say we are proud of him.
And she closed by writing: "What a joy it will be to watch this- hopefully first of many finals".
The 6'8"-tall Anderson has the bigger weapons against Carreno Busta's solid dirt-balling skills".
Anderson and Carreno Busta have played each twice before in their career, and the South African won both those matches.
Martina Hingis will play in the finals of both women's doubles and mixed doubles at the U.S. Open. It was the first time when Anderson's game was stretched to four sets but the Italian failed to stop Anderson's stunning run at the US Open, losing by 6-4, 6-3, 6-7, 4-6. Anderson broke on the next point.
After dropping the opening set, Anderson responded in a big way.
"After the first set I changed it a little bit, changed my tactic, strategy a little bit".
However, Anderson was just too solid as it soon became a one-way traffic, claiming the next three games to open up a huge 4-1 lead.
I like Nadal to win another grand slam title.
The Argentine closed out the first set with a lightning quick forehand.
"To be seeded here in US Open, I was seeded number 12".
However, his last loss at this stage came on the same NY hard courts in 2009 at the hands of Del Potro, who went on to shock five-time champion Federer in the final.
Tecau and Rojer eliminated top-seeded Henri Kontinen and John Peers in the semifinals.
The 28th seed now awaits either Rafael Nadal or Juan Martin del Potro for the championship match. Across the first five rounds, he has dropped just two sets and played dominant tennis everytime he stepped on the court.
The matches Friday offer quite a contrast in experience and name recognition.
In total, Nadal will bid for a 16th Grand Slam title in what will be his fifth meeting with Anderson.
The other semifinal features a pair of past champions at Flushing Meadows.
Anderson, born in Johannesburg in May 1986, had never gone beyond the fourth round in more than a dozen appearances at Grand Slam events. "He said:" If he's in the final, he can beat everyone.
Del Potro has been virtually running on empty.