Sports News Roundup: Olympics-Tennis-Australian world number one Ash Barty out in first round; Olympics-Tennis-Andy Murray withdraws from singles at Games due to injury and more

Across all platforms, including NBCOlympics.com and the NBC Sports app, 17 million people watched the ceremony, NBCUniversal said in an email. Olympics-Tunisia and Japan stun swimming superpowers as Barty and Murray exit Surprise gold medal joy in the pool for Tunisia and Japan and an Aussie world record contrasted with abject misery for some of the world's best athletes whose Olympics were over in a flash on a dramatic Sunday in Tokyo.

Following is a summary of current sports news briefs.

Olympics-Tennis-Australian world number one Ash Barty out in first round

Australia's tennis world number one Ash Barty was beaten in the first round of the Tokyo Olympics on Sunday, losing to Sara Sorribes Tormo 6-4 6-3. The Spaniard will next play either France's Fiona Ferro or Anastasija Sevastova of Latvia after the biggest win of her career.

Olympics-Tennis-Andy Murray withdraws from singles at Games due to injury

Britain's defending Olympic champion Andy Murray pulled out of the Tokyo 2020 men's singles tournament on Sunday ahead of his first-round match. The 34-year-old, who had been due to play Canada's Felix Auger-Aliassime, was sidelined by a thigh strain.

Olympics-Basketball 3x3-Serbia top Poland to stay perfect in men's division

Top-seeded Serbia remained perfect in the Olympic men's 3x3 basketball tournament in Tokyo on Sunday after coming from behind to beat Poland to win their third straight game. The Russian Olympic Committee team seeded second, was upset 21-16 by Belgium, who are now 2-1 after downing the powerhouse Latvian squad on Saturday.

Tokyo Olympics opening draws 16.7 million U.S. TV viewers, a 33-year low

NBC's broadcast of the Tokyo Olympic Games opening ceremony drew 16.7 million viewers, the smallest U.S. television audience for the event in the past 33 years, according to preliminary data from Comcast-owned NBCUniversal on Saturday. Across all platforms, including NBCOlympics.com and the NBC Sports app, 17 million people watched the ceremony, NBCUniversal said in an email.

Olympics-Tunisia and Japan stun swimming superpowers as Barty and Murray exit

Surprise gold medal joy in the pool for Tunisia and Japan and an Aussie world record contrasted with abject misery for some of the world's best athletes whose Olympics were over in a flash on a dramatic Sunday in Tokyo. Japan secured its second Olympic gold with Yui Ohashi's victory in the 400m women's medley, but it was Tunisia's Ahmed Hafnaoui who stunned swimming superpowers with a win in the men's 400m freestyle.

Olympics-Swimming-Tunisia, Japan celebrate unexpected gold, Australia smash world record

Tunisia and Japan celebrated unexpected golds on the opening day of swimming medal events before normal service was resumed with the Australian women's 4x100m freestyle relay team smashing their own world record on the way to the title in Tokyo. Chase Kalisz settled American nerves by delivering the country's first gold of these Games, winning the men's 400m medley as part of a U.S. one-two with Jay Litherland.

Olympics-Surfing-Surfers ride wave of emotion to make Olympic history

Some of the world's top surfers made history on Sunday as their sport made its long-awaited Olympic debut, with Brazil's Italo Ferreira and American Carissa Moore emerging victorious in the first heats at the Tokyo Games. "I'm so stoked, it's a special event and I've been training a lot these last couple of months, I'm so glad to be here," Ferreira told reporters after edging out Hiroto Ohhara, Leonardo Fioravanti and Leandro Usuna to qualify directly for the third round.

Olympics-Skateboarding-Horigome brings Japan skateboarding's first Olympic gold

Yuto Horigome of Japan claimed the first Olympic gold medal in skateboarding when he won the men's street final in Tokyo on Sunday. Kelvin Hoefler of Brazil won silver, while Jagger Eaton of the United States clinched the bronze.

Olympics-Skateboarding-Huston, Horigome advance to finals in skateboarding's debut

Skateboarding star Nyjah Huston of the United States and hometown favorite Yuto Horigome advanced to the finals of the men's street event on Sunday in skateboarding's historic debut at the Olympics. Huston, 26, recovered his form in the final two tricks after a stumbling start in his heat, a star-studded pack that included France's, Aurelien Giraud.

Olympics-Swimming-Peaty sheds moustache but wins by much more than a whisker

World record holder and defending champion Adam Peaty shaved his mustache but won, as usual, by much more than a whisker as he powered through to the Tokyo Olympics 100m breaststroke final with the fastest time on Sunday. The 26-year-old Briton won his morning semi-final comfortably in 57.63 seconds, slower than the 57.56 in Saturday's evening heats but more than a second quicker than China's Yan Zibei.