The 25-year-old American reached the last four of a tournament in this category for the first time, just below the Grand Slams.
Winner of only one tournament on the ATP Tour, in Delray Beach in 2018, he will face Friday the Russian Daniil Medvedev (6th) or the Spaniard Alejandro Davidovich (28th), opposed later in the day in the United States.
"I'm really happy. I feel like when I'm mentally good, I'm one of the best players in the world. Today it's not just about reaching the semi-finals, I'm happy to beat a guy like him, who has played so well lately," said Tiafoe.
It is indeed with authority and flawlessness, that he stopped Norrie, one of the players in form of the moment. The Briton had just won in Rio De Janeiro by taking the best in the final on the Spanish prodigy Carlos Alcaraz (2nd).
Dominating in the exchanges, the American discouraged his opponent's attempts at the net with passing and constant pressure, while shining himself on the fly (12/15 successful).
His lone rider slowed down slightly, when the 27-year-old Briton broke in the second set to get back to 5-4. But Tiafoe still had a lead and he didn't flinch to finish in 1:39.
"In the end it was a bit difficult, but it was one-sided and I'm really happy with my level of play. I'm cunning, I move well and I don't give away too many free points. I've progressed tremendously as a player and it shows," he added.
The American, who had never before passed the 3rd round in the Californian desert, is currently making a perfect run since he has not lost a set in four matches.
© 2023 AFP