Olympic champion Ashton Eaton started his quest for the decathlon world title with a season-best 100 metres run as the athletics world championships kicked off on Saturday.

The American ran 10.35 seconds for 1,011 points to lead Canadian Damian Warner (10.43, 992 points) and holder Trey Hardee of the U.S. (10.52, 970).

Also scheduled for the morning session at a sparsely filled but sun-flooded Luzhniki stadium were women’s discus and men’s pole vault qualifying, men’s 100m preliminaries and men’s 800m heats.

The day’s finals are the women’s marathon (1000 GMT) and men’s 10,000m (1455 GMT), before Jamaican superstar Usain Bolt is to appear in the 100m heats from 1615 GMT onwards.

A record 1,974 athletes from 206 countries have entered the biggest single sports event of the year, which runs until August 18.

The Russian hosts suffered a late triple blow, with women’s 3,000m steeplechase world and Olympic champion Yulia Zaripova pulling out injured. Olympic 50km walk champion Sergey Kirdyapkin and three-times 20km walk world champion Olga Kaniskina also withdrew, reportedly for health reasons.

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