Djokovic Starts Olympic Mission As Pogacar Targets Road Race Gold

History-chasing Novak Djokovic launches his quest for Olympic tennis glory, while Tour de France champion Tadej Pogacar goes for one of 11 gold medals on offer Saturday as the pandemic-delayed Tokyo Olympics finally rumble into life.

After Japanese tennis star Naomi Osaka lit the cauldron in Friday's opening ceremony, more than 20 sports from archery to weightlifting spring into action following a one-year postponement to the Games over the coronavirus pandemic.

The opening ceremony took place before empty stands with Tokyo in a state of emergency, a scenario that will become a familiar sight with fans banned from all but a handful of venues.

Djokovic had cast doubt over whether he would participate because of the strict Covid-19 protocols and lack of crowds, but the possibility of the Golden Slam -- winning all four majors and the Olympics -- proved impossible to resist.

"Without the key element of any sports events, the crowds, the fans, that energy, it's different, but it is still the Olympic Games," said Djokovic.

"I was in a dilemma for a little bit, but I decided to come, and I'm glad because there are many more things that are beautiful about the Olympic Games. So I will try to focus on those things."

The undoubted favourite and 2008 bronze medallist is hoping to emulate Steffi Graf's 1988 feat of winning the Golden Slam after already snapping up the Australian Open, French Open and Wimbledon this year.

Osaka's much-anticipated return to court was delayed by 24 hours after she was removed from Saturday's schedule, perhaps because of her turn in the opening ceremony.

Osaka has not played since her shock French Open pull-out over mental health concerns in late May, when she abandoned her Roland Garros campaign after the first round.

But the 23-year-old said that after taking several weeks to "recharge and spend time with my loved ones" she "could not be more excited to play in Tokyo".

"An Olympic Games itself is special... I hope I can make them (her home fans) proud," she recently wrote in Time Magazine.

The first gold medal will come in the women's 10-metre air rifle, which gets under way just before the road race cyclists set off from Musashinonomori Park.

The demanding 234km route climaxes at the Fuji International Speedway racing circuit, with riders facing five climbs around the iconic Mount Fuji, the highest point in Japan at an altitude of 3,776m (12,388ft).

Pogacar headlines a star-studded peloton that includes 2016 champion Greg Van Avermaet and his Belgian team-mates Remco Evenepoel and Wout van Aert.

The United States women's football team, Olympic champions in four of the six past editions, will look to bounce back from a humbling 3-0 loss to Sweden when they take on New Zealand in the second round of group games.

Swimming begins with heats in the men's 400m individual medley, where Japan's Daiya Seto is the favourite, before reigning champion Sarah Sjostrom, still recovering from a fractured right elbow, lines up in the women's 100m butterfly.

Olympic and world champion Adam Peaty is the one to watch in the men's 100m breaststroke, while Hungarian great Katinka Hosszu starts her fifth Games in the women's 400m medley.

Three-on-three basketball, played with a single hoop, tips off for the first time following its addition to the Olympic programme, which features four new sports -- karate, skateboarding, sport climbing and surfing.

A second shooting gold will be at stake Saturday in the men's 10m air pistol, with the final of archery's mixed team event to follow.

Two golds are up for grabs in each of the judo, taekwondo and fencing competitions, while the women's 49kg category will be the first of 14 weightlifting golds to be decided.

Group play also opens in the badminton, hockey, beach volleyball and men's handball competitions.