There were plenty of jokes in Flushing Meadows about Federer facing an opponent whose name sounded so close to longtime rival Rafael Nadal's, but Federer wasn't laughing when the 190th-ranked qualifier from India took the first set.
But Federer soon took control to avoid losing in the first round of a Grand Slam for the first time since the 2003 French Open.
Olympic champion Monica Puig was distraught after her first-round loss at the U.S. Open — and what bothered her the most, she said, was the way she found out that her former coach, Kamau Murray, had left her to go work with Sloane Stephens.
After a 6-3, 6-3 loss to Rebecca Peterson on Monday, Puig said she did not hear about the change from Murray and instead got word from others and from photos on social media.
Puig said: "It came as a huge shock."
Murray coached Stephens to the 2017 U.S. Open title but they subsequently parted ways.
He is back with her at Flushing Meadows this year.
Roger Federer will have to climb out of a hole to maintain his perfect record in the first round of the U.S. Open.
Federer lost the first set 6-4 to qualifier Sumit Nagal of India, who is 0-4 in ATP Tour matches. Federer has won 1,223.
And he's 18-0 in the first round of the U.S. Open, where he won five straight titles from 2004-08. He is the men's career leader in Grand Slam singles titles with 20.
Serena Williams' first U.S. Open meeting with Maria Sharapova turned out like every other matchup they've had in the last 14 years.
Williams rolled into the second round with a 6-1, 6-1 victory, beating Sharapova for the 19th straight time and taking a 20-2 lead in their rivalry.
Williams, the No. 8 seed, took control by winning the final five games of a 24-minute opening set, then the first two of the second set. She took away Sharapova's only real chance to make it close by fighting off a couple break points while serving with a 2-1 lead.
Sharapova hasn't beaten Williams since a pair of victories in 2004, including at Wimbledon.
Serena Williams is making quick work of her first U.S. Open matchup with Maria Sharapova.
Williams took the first set 6-1 in just 24 minutes, winning the final five games after Sharapova held the first time she served.
Williams has 23 Grand Slam singles titles and Sharapova has five, and they had met at every other major tournament. But while Williams is seeded No. 8 and was a finalist last year in Flushing Meadows, Sharapova is far off the form that carried her to No. 1.
Williams has dominated their rivalry, winning 18 straight to take a 19-2 lead, and appeared on her way to easily extending that after winning 27 points to Sharapova's 12 in the opening set.
Lesia Tsurenko of Ukraine has withdrawn from the U.S. Open because of an injury to her right elbow.
Tsurenko, ranked No. 40, will be replaced in the draw by 131st-ranked Xiyu Wang of China, a "lucky loser" who had been eliminated in the qualifying rounds.
A sculpture of tennis great Althea Gibson has been unveiled at the U.S. Open, honoring the accomplishments of the first African-American to win her country's national title.
Gibson, who died in 2003 at age 76, won the U.S. National Championships (now the U.S. Open) in 1957. Her other Grand Slam tournament singles titles included the French Open in 1956, Wimbledon in 1957 and 1958, and another U.S. title in 1958.
Billie Jean King, who helped unveil the granite sculpture near Arthur Ashe Stadium, called Gibson the Jackie Robinson of tennis who "carried on the legacy of equality" for future generations.
But there was just one problem, according to her former doubles partner: The granite bust of Gibson doesn't look much like her.
Eighty-five-year-old Angela Buxton, who made the trip from London for Monday's unveiling, said: "It doesn't resemble her at all. ... Maybe I said the wrong thing but that's how I see it."
Buxton added that the statue itself is not as important as Gibson's legacy and the fact that people are celebrating it.
Reilly Opelka's first main-draw match at the U.S. Open went about as well as possible: The 6-foot-11 (2.11-meter) American hit 26 aces in a 6-3, 6-4, 6-7 (6), 6-3 victory over 11th-seeded Fabio Fognini of Italy.
The only real slip-up by Opelka came when he served for the match ahead 6-5 in the third set. Still, after getting broken there and eventually dropping that set, Opelka recovered quickly to grab the fourth.
Opelka, currently ranked a career-high 42nd, acknowledged that his serve wasn't at its very best, but said the victory "shows that I've got more than that to back it up."
He turns 22 on Wednesday, when he plays in the second round.
His best Grand Slam showing was a third-round run at Wimbledon last month.
Top-seeded Novak Djokovic felt good enough after his workmanlike first-round victory at the U.S. Open to do a little dancing.
Djokovic, who is now 34-1 in his last 35 Grand Slam matches, dispatched Spaniard Roberto Carballes Baena 6-4, 6-1, 6-4.
He then gave an on-court interview in which he acknowledged dancing in Central Park as part of his pre-match preparation. Djokovic promptly went to his bag and pulled out two rackets that he used as faux maracas while he showed off his Latin dance moves to the Arthur Ashe Stadium crowd.
Djokovic, winner of this year's Australian Open and Wimbledon crowns, is seeking his fourth U.S. Open and 17th Grand Slam tournament title.
College tennis may no longer be in the plans for Jenson Brooksby. He's got more work to do in New York.
Tomas Berdych's work in tennis may be done.
Brooksby, an 18-year-old Californian, beat Berdych 6-1, 2-6, 6-4, 6-4 for his first career Grand Slam win and said afterward that he may reconsider his plans to play at Baylor University after the U.S. Open.
It was his second straight year playing in the tournament, having received a wild card last year. This time, he made it through qualifying and then took advantage of a clearly limited Berdych, who has battled injuries for much of this season.
Berdych, the 2010 Wimbledon runner-up and a 2012 U.S. Open semifinalist, said after the match he was "very close" to considering retirement. The 33-year-old Czech has missed five months this year with back and left hip injuries, and he fell out of the top 100 earlier in April for the first time since Jan. 26, 2004.
French Open champion Ash Barty was forced to come back to defeat Zarina Diyas 1-6, 6-3, 6-2 at the U.S. Open.
The second-seeded Barty, who amassed 36 unforced errors and got less than half of her first serves in, was thoroughly dominated in the first set and did not begin to come alive until the match was knotted at 3-3 in the second set.
She went on to win nine of the next 11 games, the last ending when the No. 80-ranked Diyas sailed a forehand long.
Among other notable results, third-seeded Karolina Pliskova overcame 32 unforced errors to survive her first-round match over Czech qualifier Tereza Martincova 7-6 (6), 7-6 (3). Eugenie Bouchard, a former Wimbledon finalist and top-10 player, lost her 11th straight tour match to 12th-seeded Anastasija Sevastova 6-3, 6-3. And former Olympic gold medalist Monica Puig fell to Rebecca Peterson of Sweden 6-3, 6-3.
Kei Nishikori became the first player into the second round at the U.S. Open when qualifier Marco Trungelliti had to retire with the 2014 U.S. Open runner-up leading 6-1, 4-1.
Nishikori is the No. 7 seed this year after reaching the semifinals in Flushing Meadows last year.
Trungelliti, an Argentine playing in his first Grand Slam main-draw match since the 2018 French Open, needed treatment on his upper body during a changeover in the second set. He then whacked a ball in frustration after a serve hit the net, and said he couldn't continue playing.
Trungelliti was the key witness in a match-fixing probe that resulted in the three Argentine players receiving bans for gambling-related activities. Best known of the three was Nicolas Kicker, at No. 84, the highest-ranked player convicted so far of fixing matches.
Play has begun at the U.S. Open, with third-seeded woman Karolina Pliskova and seventh-seeded man Kei Nishikori among the first to take the courts.
That's a prelude to a big opening-day lineup that includes eight former U.S. Open champions in the lineup, including top-ranked defending champion Novak Djokovic, Roger Federer, Stan Wawrinka and Angelique Kerber.
The main event comes in the opening night match on Arthur Ashe Stadium, when Serena Williams and Maria Sharapova face each other at the U.S. Open for the first time. Williams has won 23 Grand Slam singles titles, Sharapova five.
Weather is not a factor. Players took the courts under partly cloudy skies, with no rain in the forecast and an expected high of 75 degrees (24 Celsius).
The year's last Grand Slam tennis tournament gets started with quite a matchup: Serena Williams and Maria Sharapova are scheduled to face each other at the U.S. Open for the first time.
The two stars meet in Arthur Ashe Stadium on Monday night.
Williams has won 23 Grand Slam singles titles, Sharapova five. Both own a career Grand Slam. Both have been ranked No. 1.
As defending champion and top seed Naomi Osaka put it: "Of course I'm going to watch it. I know you all are going to watch it. I think everyone in New York is going to watch it."
And not just in New York.
Other past U.S. Open champions in action on Day 1 include defending champion Novak Djokovic, Roger Federer and Williams' older sister, Venus.
More AP Tennis: https://www.apnews.com/apf-Tennis and https://twitter.com/AP_Sports