The match ended in 52 minutes as Williams played her forehand into the net.
Tennis great Roger Federer has issued a tacit apology for inadvertently provoking a war of words with temperamental local Bernard Tomic ahead of the Australian Open.
Former world number four and Australian Open runner-up Dominika Cibulkova announced her retirement on Tuesday.
Earlier on Wednesday, Czech Karolina Pliskova was forced to withdraw from the tournament due to a viral illness.
Nadal had a solid start, but the 35-year-old struggled physically towards the end of the contest
Factbox on Switzerland's Roger Federer, who defeated Rafael Nadal in the Australian Open men's singles final on Sunday.
Novak Djokovic recovered from a slow start as he continued the bid to retain his world number one ranking with a 4-6, 6-2, 6-3 win over 14th-seeded Bulgarian Grigor Dimitrov in the Paris Masters third round.
Novak Djokovic and Serena Williams are top seeds at the major starting Monday
World number one Novak Djokovic rediscovered a ruthless streak when it mattered most to stay on course for a career slam with a nail-biting 6-3, 6-3, 5-7, 5-7, 6-1 win over Andy Murray to reach the French Open final on Saturday.
IMAGES from Day 1 of the Wimbledon Championships played on Monday.
Polish fifth seed Agnieszka Radwanska was the highest women's casualty at the Miami Open on Saturday, blown away for the second time this year by Croatian Mirjana Lucic-Baroni.
Rediff.com gives you a throwback to an eventful 2017, in pictures.
Australia's number one tennis player Nick Kyrgios has blamed "unfair and unjust treatment" at the hands of his country's Olympic Committee for his decision not take part in the 2016 Olympic Games in Rio de Janeiro.
If there is a new member of the grand slam champions' club this weekend, nobody should be surprised -- the conditions at this year's sodden, chilly French Open suit the underdog.
Rafael Nadal is hunting a record-extending and almost unbelievable 12th Roland Garros title is remarkable in itself.
'It's a new era and will be like adapting to a different routine. Moya has come with new ideas and new methods of working that have worked well and we are excited'
Nick Kyrgios and Bernard Tomic gave Australia an unwanted reputation as a breeding ground for tennis brats during a tempestuous 2015 and the pair will be firmly under the spotlight in front of home crowds at Melbourne Park. With former world number one Lleyton Hewitt set to retire and the last of his two grand slam titles at the 2002 Wimbledon championships a distant memory, Australia has long yearned for a new force in men's tennis to challenge at the majors. Tomic, 23, and Kyrgios, 20, have both been tagged as the future of the sport in the country but the excitement generated by their undeniable talent gave way to dismay last season as the pair hogged the headlines for all the wrong reasons.
Federer, Nadal and Djokovic had made it near impossible for their peers to live, and thrive, amongst them. But the coming generation, which hasn't been as scarred by defeat at the hands of the Big 3, may make tennis unpredictable again.
Both players burn with heaps of motivation to hoist the winner's trophy at Arthur Ashe Stadium in the last grand moment of the 2015 slam season.
The 21-year-old German, one of the brightest stars in men's tennis, is yet to progress beyond the quarter-finals at a Grand Slam.
'I feel happy to be part of this rivalry, but at the same time, I played even more matches with Novak (Djokovic) than with Roger in such important matches, too'
With the American men experiencing their longest US Open title drought in the Open era, Venus Williams led the American charge into round two on Monday with a 6-3, 3-6, 6-2 win over Viktoria Kuzmova of Slovakia.
US Open, the final Grand Slam of the season, starts Monday, August 28, at Flushing Meadows in New York.
List of French Open men's singles champions:
Roger Federer is the oldest male player to win a Grand Slam title since Australia's Ken Rosewall won at Melbourne Park in 1972 at the age of 37.
Images from Day 1 of the 2020 French Open in Paris on Sunday.
News of all that's transpired on and off the tennis courts.
Roger Federer and Rafael Nadal take to Rod Laver Arena to reprise one of the great sporting rivalries of the modern age on Sunday, a fitting climax to an Australian Open which has sent tennis back to the future.
The Serb, who turned 30 last month, will drop outside the top two for the first time since march 2011 on Monday -- quite a contrast to a year ago when his domination of men's tennis was complete after winning the French Open for the first time.
Nadal surpassed the haul of Roger Federer and Novak Djokovic.
Djokovic, the ninth seed, was originally scheduled to play Australian Open semi-finalist Chung Hyeon but the 22-year-old South Korean withdrew with a back injury about an hour before the match was due to start.
Murray, who is attempting to return to the top of the tennis world after undergoing hip surgery in January, was out of sorts in the first set of the rain-delayed match, losing three service games behind some uncharacteristically soft second serves.
A pioneering Kei Nishikori blazed a new trail for Japanese tennis with a shock win over World No 1 Novak Djokovic at the U.S. Open on Saturday, becoming the first man from Asia to book a place in a Grand Slam final.
Novak Djokovic maintained his unbeaten record against Frenchman Gael Monfils with a 6-3, 6-2 win in the semi-finals of the Rogers Cup in Toronto on Saturday, while Japan's Kei Nishikori also reached the final after beating Swiss second seed Stan Wawrinka.
'He can say what he wants, I don't have a problem with it. Does he show me the same amount of respect that most other players do? No, he doesn't, but that's the way he communicates these days'
Andy Murray is undefeated since September, has won 24 matches in succession and his win-loss record since losing to Novak Djokovic in the French Open final is 53-3.
Images from the matches played at the Australian Open on Sunday.
Osaka survives test to reach last 16
World number one Novak Djokovic scrapped his way into the US Open final for a seventh time on Friday with a confounding 6-3, 6-2, 3-6, 6-2 win over enigmatic Frenchman Gael Monfils.
Rediff.com gives you a peek of the big names who were in attendance of the US Open.
