TOKYO -- Canada's Damian Warner opened his quest for an Olympic decathlon title in emphatic fashion.

The 31-year-old from London, Ont., ran 10.12 seconds in the 100 metres to tie his decathlon world record in the event.

Warner then crushed the field in the long jump, soaring 8.24 metres, the longest in Olympic decathlon history and a distance that would have earned him a bronze medal in the open men's long jump earlier in the week.

Warner was 11th in the shot put, then cleared 2.02 metres in high jump to tie for eighth, but still maintained a lead with 3.788 points after four of 10 events. The 400 metres was the final event on Wednesday.

Australian Ashley Moloney was second with 3647.

Canadian teammate Pierce LePage dropped a spot to third place after the high jump, with 3,567 points.

Warner is the No. 1-ranked decathlete in the world this year after shattering his Canadian record at the Hypo-Meeting in Gotzis, Austria. His score of 8,995 there was the fourth best in history.

LePage, from Whitby, Ont., ran the 100 in 10.43, the third-fastest time on the morning. His 7.65 metres in long jump was second-best, and his throw of 15.31 in shot put was fourth.

Warner's Canadian record performance in May came after a winter of training in an unheated hockey arena in London. COVID-19 protocols shut down the University of Western Ontario indoor track facility, so his coaches outfitted the arena with a 40-metre track runway, pole vault and high jump pits, and a throwing circle.

The decathletes are facing gruelling conditions in Tokyo. The temperature at Olympic Stadium at 9 a.m. for the 100 metres was already 33 C, but felt like 47 C with the humidity.

Thursday's weather forecast calls for sun and a high of 35 C.

The decathlon features 10 events over two days. The 400 metres was the final event on Wednesday. Thursday's Day 2 events are the 110-metre hurdles, discus, pole vault, javelin, and the 1,500 metres.

In other events, Genevieve Lalonde of Moncton, N.B., was 11th in the women's 3,000 steeplechase, shaving a couple of tenths of a second off her Canadian record to run 9:22.40.

Gabriela DeBues-Stafford clinched her spot in the women's 1,500 final by finishing third in her semi in a season's best 3:58.28. Her time was the third fastest on the night in fastest semifinal in Olympic history with five women dipping under the four-minute mark.

Her younger sister Lucia Stafford was sixth in her semifinal (a personal best 4:02.12), and didn't advance.

This report by The Canadian Press was first published Aug. 4, 2021.