2016 US Open: Stan Wawrinka (SUI) poses with the trophy after his match against Novak Djokovic (SRB)
Sep 11, 2016; New York, NY, USA; Stan Wawrinka (SUI) poses with the trophy after his match against Novak Djokovic (SRB) on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Susan Mullane-USA

Stan Wawrinka defeated World No. 1 Novak Djokovic in the 2016 U.S. Open championship Sunday in New York. Defending champion Djokovic won the first set 7-6(1), but Wawrinka gained footing and held on with three straight wins (6-4, 7-5, 6-3). Djokovic lauded his opponent in a statement to the media.

Wawrinka has now claimed his 3rd Grand Slam, following his Australian and French Open victories. Spectators attribute Wawrinka’s victory to his powerful backhand.

Wawrinka net worth rises, Djokovic congratulates Swiss athlete

The victory adds $3.5 million (around AU$4.6M) for Wawrinka, whose net worth was previously estimated to be at $12 million to $15 million (AU$16M to AU$20M).

Speaking to the media, Wawrinka said the emotional crowd and the atmosphere in the stadium made for an “amazing night.”

"I never had a goal to win a Grand Slam but I am trying as best I can. Match after match I was playing better," BBC quotes Wawrinka.

U.S. Open Highlights: Stan Wawrinka wins vs Novak Djokovic
Sep 11, 2016; New York, NY, USA; Novak Djokovic (SRB) and Stan Wawrinka (SUI) at the trophy presentation ceremony after their match on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Susan Mullane-USA TODAY Sports

On the other hand, Djokovic had to get treatment twice for his foot injury, which presumably caused fatigue, and subsequently, a significant loss in concentration and energy for the world number one.

"Congratulations, Stan, to your team as well. This has been absolutely deserved today. You were more courageous player in the decisive moment and he deserves his title," Djokovic tells Wawrinka after his defeat.

Djokovic has so far made seven trips to the U.S. Open final, winning the championship twice. He called Wawrinka “a great champion.”

BBC reports Wawrinka, 31 years old, has become the oldest winner at Flushing Meadows Ken Rosewall won in 1970 at 35.

LOOK: More photos from the 2016 U.S. Open championship

2016 U.S. Open tennis tournament-RTSN9RC
Sep 11, 2016; New York, NY, USA; General view of the playing of the national anthem at Arthur Ashe stadium before the match between Novak Djokovic of Serbia and Stan Wawrinka of Switzerland in the championship match on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Anthony Gruppuso-USA TODAY Sports

Novak Djokovic of Serbia at the 2016 U.S. Open tennis tournament --RTSN9ZV
Sep 11, 2016; New York, NY, USA; Novak Djokovic of Serbia returns a shot to Stan Wawrinka of Switzerland in the championship match on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Anthony Gruppuso-USA TODAY Sports

2016 U.S. Open tennis tournament: Stan Wawrinka of Switzerland hits to Novak Djokovic of Serbia--RTSN9SG
Sept 11, 2016; New York, NY, USA; Stan Wawrinka of Switzerland hits to Novak Djokovic of Serbia in the men's singles final on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Robert Deutsch-USA TODAY Sports
Stan Wawrinka of Switzerland celebrates match point in his player box with girlfriend Donna Vekic --RTSNAB7
Sep 11, 2016; New York, NY, USA; Stan Wawrinka of Switzerland celebrates match point in his player box with girlfriend Donna Vekic after his match against Novak Djokovic of Serbia on day fourteen of the 2016 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Reuters/Susan Mullane-USA TODAY Sports