Italian top seed Jannik Sinner took down ailing Briton Jack Draper 7-5 7-6(3) 6-2 to reach the U.S. Open final on Friday, overcoming muggy conditions in a chaotic match at Arthur Ashe Stadium.

Sinner appeared to have suffered a wrist injury when he fell over in the second set but rallied to reach his second major final after winning the Australian Open earlier this year.

Little went right for Draper, who vomited three times in the second set as he struggled with the heat and humidity that also left his shirt soaked in sweat.

Ten double faults also failed to help the 22-year-old's bid to reach a Grand Slam final for the first time.

"It was a very physical match as we saw. I just tried to stay there mentally," said Sinner, who has survived the intense pressure of being the overwhelming favorite to win his first U.S. Open title following early exits of Novak Djokovic and Carlos Alcaraz.

Sinner will play the winner of an all-American semi-final between Taylor Fritz and Frances Tiafoe on Sunday.

Sinner and Draper traded early breaks in the first set but the momentum swung in the Italian's direction when the Briton dropped serve in the 11th game with a double fault.

Draper held his serve through a marathon, four-deuce opening game in the second set but could not convert a break point chance in the second game. From then on, the contest turned into a nightmare for the 25th seed.

The Briton dropped his racket and ran to his bench to change his sweat-drenched shoes after the sixth game and he threw up twice in the eighth game, waving off the umpire's attempts to pause the match and bring out a crew to clean the mess.

Sinner looked to be in trouble after he slipped and fell in the ninth game, wincing in pain after bracing himself with his left hand in the fall.

One physio came to massage the Italian’s wrist while another came to help the ailing Draper during the changeover.

Draper requested another set of fresh shoes from his locker and battled on, vomiting for a third time in the 12th game before Sinner sprinted through the tiebreak.

Sinner got the critical break in the final set with a terrific backhand winner down the line in the sixth game and Draper looked miserable as he sipped a soda on his bench after the seventh game.

Sinner closed it out with a backhand winner on match point, embracing his opponent at the net.

Earlier in the day, Latvian Jelena Ostapenko and Ukraine's Lyudmyla Kichenok won the women's doubles crown, beating Chinese-French pair Zhang Shuai and Kristina Mladenovic 6-4 6-3 after coming up short in the Australian Open final.