The Serb collapsed from a set and a break ahead as German fourth seed Zverev won 1-6, 6-3, 6-1 TOKYO: World number one Novak Djokovic crashed out of the Tokyo Olympics on Friday and a defeated American swimmer launched doping accusations against a Russian rival. As the athletics events began in a stadium deprived of spectators by anti-coronavirus measures, Jamaican sprint queen Shelly-Ann Fraser-Pryce made an impressive entrance. Djokovic"s bid for a calendar Golden Grand Slam -- all four Grand Slam tournaments plus the Olympics -- was dramatically ended by Alexander Zverev. The Serb collapsed from a set and a break ahead as German fourth seed Zverev won 1-6, 6-3, 6-1 to set up a final against Russian Karen Khachanov. In a bitter row at the pool, American swimmer Ryan Murphy accused Evgeny Rylov of doping after he was beaten by the Russian in the 200m backstroke. Murphy said he had been "swimming in a race that"s probably not clean". Rylov said he was "surprised" by Murphy"s "strange" suggestion. The Russian Olympic Committee (ROC) hit back on Twitter, saying "the broken record is once again playing the song about Russia doping and someone is diligently pressing the button on the English-language propaganda". The Russian Anti-Doping Agency said Rylov had been tested three times this year and that he was "prepared and clean". Russia are banned from Tokyo 2020 after being found guilty of state-sponsored doping, meaning their athletes cannot use the Russian flag and anthem. But more than 330 Russian athletes have been allowed to compete under the ROC moniker, and they had won 10 golds by Friday evening to lie fourth in the medals table. As competition began in the 68,000-capacity Olympic Stadium, Fraser-Pryce successfully launched her bid to become the first woman to win an individual Olympic athletics event three times. The Jamaican, 100 metres champion in 2008 and 2012, shut down with 20 metres remaining and strode over the line for a comfortable first-round victory in 10.84sec. One of her rivals, the Ivory Coast"s Marie-Josee Ta Lou, blasted to an African record-equalling 10.78sec and reigning champion Elaine Thompson-Herah of Jamaica recorded 10.82sec on what appears to be a fast track. "If you notice the heats, there"s some really quick running. It"s good for female sprinting. It"s long overdue," Fraser-Pryce said. The semi-finals and final of that event take place on Saturday evening. World record-holder Karsten Warholm of Norway strolled to victory in his heat of the 400m hurdles heat, an event that could be one of the highlights. "It was nice to get out on the track again," said Warholm. "I"ve been here for two weeks already, I"m starting to get bored so it was very nice to get around." Qatar"s Abderrahman Samba eased through but said he felt the absence of spectators: "It was really, really difficult. I really missed the crowd." In the pool, South Africa"s Tatjana Schoenmaker was overjoyed after becoming the first South African woman to win an Olympic swimming gold for 25 years as she obliterated the eight-year-old world record in the 200m breaststroke, timing 2min 18.95sec. Australia"s Emma McKeon claimed her fourth medal in Tokyo as she blazed to the women"s 100m freestyle title in a new Olympic record of 51.96sec. Hong Kong"s Siobhan Haughey -- one of the surprises of the swimming events -- earned another silver medal to add to that from the 200m freestyle. French judo superstar Teddy Riner came up short in his bid to win a historic third consecutive heavyweight title, losing to Russia"s world number one Tamerlan Bashaev in the quarter-final. Riner had to settle for bronze. The shadow of coronavirus hung over the start of the athletics with the Australian team saying three of its members would remain isolated from the rest of the squad "as a precautionary measure" after a scare. The three are classed as close contacts of US pole vaulter Sam Kendricks, who has been ruled out of the Games after testing positive for Covid-19. Ian Chesterman, the chef de mission of the Australian Olympic Committee, told a press conference: "They all tested negative which is good. They also confirmed the daily test results which have also been negative and confirmed their test results before they left Australia." Coronavirus cases are surging in Japan a week into the Games. On Friday, Tokyo 2020 organisers reported 27 new cases related to the event -- the highest daily figure yet -- although they insist there is nothing to suggest a link between the Games and rising infections in Japan.