Hundreds of athletes, including US sprinter Justin Gatlin, participated in a test event at the Olympic Stadium on Sunday, as organisers fine-tuned operations and COVID-19 countermeasures with under three months to go before the Tokyo Games.
No spectators were present in the stadium, where the Games' opening and closing ceremonies will be held, as Tokyo remains under a state of emergency to tame a rise in coronavirus infections.
Sunday's event involved 420 athletes, including nine who came from abroad to participate, with 2004 Olympic gold medallist Gatlin winning the 100 metres.
Despite the state of emergency, organisers have operated more than 11 test events since last month with no reported coronavirus cases resulting from them.
Four of those of events - volleyball, diving, marathon and Sunday's athletics - included athletes from abroad.
Gatlin said he was satisfied with the COVID-19 protocols, including daily testing and eating all his meals in his room.
"Obviously I think this competition was a precursor to see exactly how the Olympics can go off, maintaining a bubble for the athletes to be able to stay healthy, and also the citizens of Japan to be able to stay healthy with foreign athletes coming into the country," Gatlin told reporters after his race.
"I think it was a success."
Opinion surveys have shown that most Japanese oppose holding the Games this summer due to worries about the pandemic.
World Athletics President Sebastian Coe sought to ease those concerns.
"We are very empathetic to the need to be fully recognising that communities around the world are inevitably nervous about many things related to COVID," he told a news conference at the stadium.
"We take those concerns very, very seriously. The COVID protocols, particularly that World Athletics have developed over the last year and a half by our health and science teams who are extremely good at this, have consistently helped deliver events in a safe and secure environment."
Many athletes have said they want the Games to go forward.
"People are really worried about people coming from overseas as coronavirus variants are spreading, but as an athlete I want the Olympics to be held with people from various countries running," said Suzuha Kobari, after participating in the women's 100 metres in the morning session.
Japanese rhythmic gymnast Nanami Takenaka said at a separate test event the previous day that she understood there were opposing views, but that gave her team an extra reason to bring cheer through their performances.
"We'll focus on the things that we can do and when the Olympics are held we want to give our best performance so that people can smile and feel glad they took place," she said.
Sunday's event was split into morning and evening sessions testing a range of competitions from the shot put and triple jump to the pole vault, javelin and the various running disciplines.