TOKYO, Aug 5 ― Australia’s Keegan Palmer flew to a stunning skateboarding gold medal on Thursday as the USA suffered track disappointment with a major flop in the 4x100 metres relay heats.

American shot putter Ryan Crouser hurled an Olympic-record 23.30 metres to retain his title, while Portugal’s Pedro Pichardo leapt 17.98m to win the men’s triple jump.

Jamaica’s Hansle Parchment upset America’s Grant Holloway to win the men’s 110m hurdles in 13.04sec, charging through the closing stages as the world champion faltered.

"It’s unbelievable that I caught that guy (Holloway),” said Parchment, 31. "My coach reminded me to run through the line ― and that’s what I did.” 

"I don’t think a lot of people expected me to win,” added the Jamaican.

But there was a bigger disappointment for Team USA when their relay team, the world champions and pre-Games favourites, finished sixth in their heat to miss the final.

Sprint legend Carl Lewis called it a "total embarrassment” as Trayvon Bromell, Fred Kerley, Ronnie Baker and Cravon Gillespie became the first US quartet to fail to make the final from a completed heat.

"We just didn’t get the job done today,” said Kerley. "No excuses.”

At the Ariake Urban Sports Park, Palmer wrapped up the Olympics’ inaugural skateboarding programme with a brilliant gold medal in the men’s park event.

Pulling some huge airs, the 18-year-old scored a massive 94.04 points in his first run before bettering his score to 95.83, way ahead of silver medallist Pedro Barrios’s 86.14 and American Cory Juneau, who claimed bronze with 84.13.

NBA stars

The first of Thursday’s 27 gold medals came in marathon swimming, when Germany’s Florian Wellbrock won the men’s title in a time of 1hr 48min 33.7sec.

Wellbrock and third-placed Gregorio Paltrinieri ― who was struck by glandular fever before the Games ― had also medalled in the pool, with 1500m bronze and 800m silver respectively.

Also on Thursday, Kevin Durant’s United States face a threat to their men’s basketball crown in their semi-final against an Australia team stacked with NBA experience including Patty Mills and Joe Ingles.

In the other semi, France, who stunned the Americans in their opening game, must contain the scoring of Slovenia’s Dallas Mavericks star Luka Doncic if they are to reach the final.

The men’s 20km race will take place in Sapporo, hundreds of miles (kilometres) north of Tokyo after it was moved to avoid the capital’s punishing summer heat.

However, Sapporo has been battling a heatwave of its own with temperatures climbing to 32 degrees Celsius (90 degrees Fahrenheit) on Thursday.

In what is expected to be her last Olympics, 36-year-old football star Megan Rapinoe will look to sign off with a bronze when the United States play Australia in Kashima.

China will attempt to tighten their grip on the diving events by retaining the women’s 10m platform title, and the dominant Chinese will play Japan in the women’s team table tennis final.

The women’s keirin and men’s omnium are the next events up in track cycling, and Australia play Belgium in the men’s hockey final.

Also, the first Olympic medals will be handed out in sport climbing and karate, two new additions to the programme. ― AFP