Puerto Rico's Monica Puig, whose dream run to a gold medal was one of the feel-good stories of the Rio Games, came down to earth at the US Open tennis championship where China's Saisai Zheng dealt her a 6-4, 6-2 defeat in the first round.

The 22-year-old Puig was not in her best form entering the final Grand Slam event of the year and her performance on Monday confirmed the expectations of some tennis analysts.

No.2 seeded Angelique Kerber started her US Open tennis campaign with a comfortable win against Polona Hercog, who retired from the match down 0-6, 0-1.

"To be honest, it's never the way I would like to finish the match, but I went out there to feel my rhythm and start the tournament well. I played the first set really good, so this is what I will take from this match, that I'm playing my tennis," Kerber said after the match here on Monday.

The US Open got underway on Monday at the USTA Billie Jean King National Tennis Center with a new attraction -- the retractable roof on Arthur Ashe Stadium, a feature that will allow play to continue when it rains.

The $150 million retractable roof is expected to help organisers deal with the rain delays that have often plagued the final Grand Slam event on the tennis calendar.

Canadians Milos Raonic, Eugenie Bouchard, and Vasek Pospisil are gearing up for the final Grand Slam of the season, as the official draws for the US Open singles events were conducted in New York on Friday.

Competing in his first major as a Grand Slam finalist, Raonic will open his campaign against German Dustin Brown, currently ranked world No. 87. It will be their first meeting. Seeded No. 5 in New York, Raonic is in the same quarter as Rafael Nadal and same half as Novak Djokovic. En route to a potential quarter-final meeting with 14-time Slam champion Nadal, Raonic’s toughest test could be Gael Monfils in the fourth round, who he lost to at Rogers Cup in Toronto a few weeks ago. The 2016 Wimbledon runner-up will be looking to advance past the round of 16 at the US Open for the first time.

Switzerland's 17-time grand slam winner Roger Federer has decided to call an end to the current season as he announced on Tuesday that he will miss the rest of the 2016 season including the upcoming Olympic Games to be held here next month.

"I'm extremely disappointed to announce that I will not be able to represent Switzerland at the Olympic Games in Rio and that I will also miss the remainder of the season," said the 34-year-old in a Facebook post.

There was very little to choose between them in the end. In fact, World No.1 Novak Djokovic won just 2 points more than 17 time Grand Slam champion Roger Federer in the entire match, 147 to 145, but what the Serbian did do was he played the big points that little bit better, and as a result he walked away from New York for just the second time in his career, the US Open Champion.

The dream US Open final between crowd favourite Roger Federer and the world's best player at the moment Novak Djokovic finally got underway on Sunday afternoon after a 3 hour long rain delay. If there were any nerves at the start of the match, they were on the side of the 34 year old veteran, who had gone three years without a major title.

The world no.1 pairing of Martina Hingis and Sania Mirza followed up their triumph at Wimbledon earlier this year by also capturing the US Open Women's Doubles title, crushing the Australian - Kazazh pairing of Casey Dellacqua and Yaroslav Shvedova 6-3, 6-3 in the final today.

Playing in front of a near empty Arthur Ashe stadium a four hours before the Men's Singles Final gets underway, Mirza and Hingis started the match brightly and quickly confirmed their status as the favourites by clinching an early break of serve. Even when the duo dropped serve on the odd occasion in either set, they were always well in control of the contest, and barring some late nerves wrapped up the match in rather comfortable fashion.