US Open champion Stan Wawrinka was left thrilled but exhausted as Novak Djokovic praised the Swiss star for his mental strength in the final.
Wawrinka claimed a 6-7 (1-7) 6-4 7-5 6-3 win over the world number one and defending champion in the decider at Arthur Ashe Stadium on Sunday.
It marked the 31-year-old's third grand-slam title after a gruelling fortnight in New York.
"This is amazing. I came here without expecting, without putting the goal of winning it but every time I stepped on the court I was trying to win every match," Wawrinka said in an on-court interview.
"I played quite a lot of tennis, I am completely empty.
"There was so much emotion with the crowd, the atmosphere, the stadium. This is something I never had before so thank you so much. It's been amazing."
Djokovic had spent just eight hours, 58 minutes out on court heading into the final, compared to Wawrinka's 17:54.
The Serbian, who needed treatment on his feet during his loss, said Wawrinka's ability to take his chances was crucial.
Djokovic converted three of 17 break points, while his opponent was six of 10.
"We played almost four hours and I think I can speak for Stan as well, we both felt it," he said.
"We felt the demanding match we played today physically but he came out on top in the decisive moments, he was the better player, he was tough mentally, he knew what to do and I was just unlucky in some moments and that's it. That's sport.
"A few points decide a winner at this level but again, it was a fantastic couple of weeks for me."