The Asian Games began in Japan on Thursday when Qatar beat Iran in the men's basketball opening group game, the first action in the continental multi-sport showpiece that has more participants than the Olympics.

Over 17,000 athletes and officials are expected to take part in 43 sports at the Nagoya-Aichi Games -- which do not officially start until the opening ceremony on September 19 and will run until October 4.

Several events such as basketball, football, cricket, hockey and modern pentathlon will get under way before the opening ceremony.

Qatar held off a comeback from Iran to win their Group B encounter 59-35 at the Aichi International Arena in Nagoya in the first match of a men's basketball competition that will hold medal finals on September 20, the day after the opening ceremony.

Los Angeles 2028 Olympics qualifying spots are up for grabs in several sports at the Asian Games, which are returning to Japan for the first time since 1994.

Organisers hope the athletes will have a "unique experience" staying in eye-catching accommodation ranging from a cruise liner and wooden containers to standard hotel rooms.

Officials are confident that the plan will not be affected by Japan's typhoon season, which is usually in full swing in September-October.

Weather has already caused disruptions, with record rainfall on Tuesday forcing hundreds of athletes briefly to evacuate their accommodation.

Rainwater also leaked into some competition venues, with more wet weather forecast for the coming days.

Among those in action at the Games will be Philippine tennis sensation Alexandra Eala and a pair of world-class teenage talents in 15-year-old Indian cricketer Vaibhav Sooryavanshi and 13-year-old Chinese swimmer Yu Zidi.