Yusuke Suzuki captured Japan's first race walk world title and secured a spot at the 2020 Tokyo Olympics after winning gold in the men's 50-kilometer contest at the athletics world championships on Sunday.

Suzuki, who set the national 50-km race walk record earlier this year, stayed ahead of the pack despite severe heat in the Qatari capital that saw many racewalkers drop out, including defending champion and world record holder Yohann Diniz of France.

"I don't feel like (I won the title). I was just desperate to finish," Suzuki said. "The relief of just being able to reach the goal is the best. The last 16 km was a battle against anxiety."

Suzuki finished the grueling race with a time of 4 hours, 4 minutes and 20 seconds -- more than 30 minutes off the 3:23:33 world record set in 2014 by Diniz, and more than 25 minutes over his personal best, the current Japan record of 3:39.07 Suzuki clocked at this year's national championships in Wajima, Ishikawa Prefecture.

The 31-year-old also competes in the 20-km race walk, an event he appeared in at the 2012 London Games and for which he holds the world record.

On Saturday, Olympic hopefuls Abdul Hakim Sani Brown, Yoshihide Kiryu and Yuki Koike were all eliminated from the men's 100-km competition.

The Japanese trio finished with respective times of 10.15, 10.16 and 10.28 in the semifinals before American Christian Coleman won gold with a world-leading time of 9.76.

"The (starting) sound was quiet and I couldn't hear it at all. So I was slow in the first half," Sani Brown said. "I switched gears and ran hard from the middle but just couldn't catch up."

"It was a race that shows how important the beginning is. I wonder if there was a part where I just wasn't concentrating enough."

Koike also said he had trouble at the start of the race.

"I messed up a little at the start," he said. "It all got spoiled at the beginning, it was a waste of a race. I want to get back on my feet and get ready for the relay."