Dmitriy Markov gave Australia their first gold medal of the World Championships with a superb victory in the pole vault on Thursday.

He set a new World Championship record of 6.05m, beating the previous best mark set by the legendary Sergei Bubka, who watched from the stands.

The Belarus-born athlete triumphed in a top-class final in Edmonton, beating Alex Averbukh of Israel into second place, with Nick Hysong of the US claiming bronze.

He won by a huge margin of 20cm and the result was known long before the end of the three-hour final, which became a personal duel between Markov and the record books.

Bubka - renowned as the greatest vaulter of all time and now a leading member of athletics ruling body, the IAAF - looked on as Markov made his mark on the world stage.

At one stage Bubka's own world record of 6.14m looked under threat, but he ultimately failed with all three attempts at 6.10.

"This is the greatest day of my life," Markov told BBC TV.

"I'm still somewhere in space, but I'm really proud."

A foot injury had almost prevented Markov from competing at all.

"I was worried coming into the competition," said the 26-year-old. "I spent 10 hours yesterday icing an injury on my foot, and another three hours.

"I never expected to jump over six metres," said Markov, who became an Australian citizen in 1999, shortly before winning silver at that year's World Championships.