The 24-year-old American with Sierra Leone descent beat Andrey Rublev ninth seed 7-6 (7-3) 7-6 (7-0) 6-4 in Arthur Ashe Stadium.

Tiafoes, who stunned Rafael Nadal in the previous round, became the first American man to reach the US. Open semifinal in 16years after he defeated Russian Andrey Rublev.

Tiafoes first career Grand Slam Semifinal will come Friday against the winner of Wednesday’s Carlos Alcaraz or Jack Sinner.