NEW YORK — Taylor Fritz won six straight matches against a weak and frustrated Frances Tiafoe on Friday night at the US Open, winning 4-6, 7-5, 4-6, 6-4, 6-1 to reach his first Grand Slam final.

The victory of 12th-seeded Fritz over 20th-seeded Tiafoe, a duo of 26-year-olds who are good friends and have known each other since they competed in tournaments for under-14s, earned him a championship showdown with top-seeded Jannik Sinner on Sunday.

Fritz is the first American to appear in a major final since Andy Roddick lost to Roger Federer at Wimbledon in 2009. And if he can beat Sinner, Fritz would become the first American to win a Grand Slam trophy since Roddick won it at the US Open 21 years ago.

Fritz has now won 17 majors in 2024, the most by an American in a year since Roddick’s 17 in 2003.

From 4-all in the fourth set Friday, Fritz took control when Tiafoe’s hitting and usual confidence deserted him. After a double fault yielded a break to make it 4-0 in the fifth, Tiafoe threw his racket in the trash after more than three hours of play. Fritz repaid the favor by double faulting to end the next game, but broke right back and it was quickly over.

Fritz won 25 of 34 points in the fifth set, including the last eight points of the match; Tiafoe failed to win a single point on his second serve in the set (0-for-9).

It was Tiafoe’s 13th loss in a five-setter since the start of 2015, when he made his Grand Slam debut, the most five-setter losses at majors in that period.

ESPN Stats & Information and The Associated Press contributed to this report.