The US Open, final Grand Slam of the season, starts on Monday at Flushing Meadows in New York.
Australian actor Hugh Jackman posted a picture with tennis legend Roger Federer on Twitter.
India's big hope Yuki Bhambri crashed out of the US Open men's singles qualifiers with a three-set defeat to Japanese Go Soeda while Prajnesh Gunneswaran also suffered a tame defeat.
Nadal, back on top of the world rankings for the first time in three years, is a two-time winner in New York, his 2010 and 2013 titles forming part of his 15-Slam portfolio which was embellished by a record 10th French Open in June.
Victoria Azarenka reached the US Open final in 2012 and 2013 where she was beaten by Serena Williams on both occasions.
Rafael Nadal had slipped to as low as 13th in the ATP rankings midway through 2015.
While Sania and her Chinese partner Shuai Peng lost in the last four of the WTA event, Bopanna and his Croatian partner were outdone in a thrilling quarterfinal of ATP men's doubles event.
Rafael Nadal wore black ribbons during an earlier match in tribute to the victims of twin vehicle ramming attacks in Spain that left 14 dead.
Australia's Nick Kyrgios humbled new world number one Rafael Nadal 6-2, 7-5 to reach Cincinnati Masters semi-finals on Friday.
In the WTA event, being run simultaneously, Sania Mirza and Shuai Peng have reached the semifinals with a 6-3 6-7(1) 10-3 win over Irina-Camelia Begu and Raluca Olaru.
Nitin's big break came in 1994 when he was selected to officiate at Wimbledon.
Next for Rafael Nadal, who had a first-round bye, is a third-round matchup with 24th-ranked countryman Albert Ramos-Vinolas.
The Indo-German pair went down to the Spanish Duo of Feliciano Lopez and Marc Lopez 2-6, 7-6 (7-2), 10-6.
Williams said during her pregnancy layoff she had kept a close eye on the tennis world, including her sister Venus's run to the Wimbledon final.
Sharapova tested positive for meldonium at the 2016 Australian Open and was suspended by the International Tennis Federation, a ban that ended in April.
Ramkumar Ramanathan made it to the main draw as a lucky loser after Gael Monfils withdrew due to illness.
Five tennis players have a chance to grab the world No 1 ranking at this week's Cincinnati Open.
Third-ranked Federer said he injured his back in Montreal, where he lost in the final to Germany's Alexander Zverev.