A thunderstorm pushed back the start of the men's 20-kilometre race walk, the first event of the World Athletics Championships, by two hours on Saturday.
Athletes were minutes from starting when officials announced the delay.
The evening session of the opening day includes finals in the men's shot put, women's 10,000 metres and the mixed 4x400 relay.
World Athletics Championships, organized by the International Association of Athletics Federations (IAAF), has been held since 1983 when Finland's capital Helsinki had the honor of hosting the games for the first time.
The 2023 event's total prize pool is $8.4 million. The champions will get a total of $70,000, the runners-up will receive $35,000 and the third-place finishers will claim $22,000.
In addition to individual events, relay teams will collect between $20,000 and $80,000 per team tournament ranking.
