Robert Heffernan became Ireland's first male world champion in 30 years by defeating the Russian challenge in their own back yard to win the 50 kilometres race walk gold in Moscow.
The 35-year-old, who finished an agonising fourth at London 2012 last summer, strode away from home favourite Mikhail Ryzhov in the closing kilometres to win in a world-leading three hours 37 minutes 56 seconds.
He said: "I wanted to go to Moscow and take on the Russians in Moscow and that's what I did. I'm very proud that an Irish man can come to Russia and beat them in walking."
His country were proud too, with president Michael D Higgins saying the people of Ireland would celebrate his success.
"All of us will share in this wonderful moment for Rob and his family," said President Higgins.
"Rob came so close to success in the London Olympics and now, through hard work and dedication, he has achieved all that he deserves."
Heffernan's triumph saw him follow in the footsteps of Eamonn Coghlan, the last Irish man to take global gold when he won the 5,000m in Helsinki in 1983.
Heffernan was Ireland's first world champion of either sex since Sonia O'Sullivan triumphed over 5,000m in Gothenburg 18 years ago.
He went to Moscow in fine form and was considered a genuine medal hope for an Irish team, although few could have predicted gold.
In a composed morning run, he was with the leading pack at the halfway mark and, when one by one it was whittled down, he went toe-to-toe with Ryzhov.
Heffernan looked far fresher going into the final 5km, though, and was away and gone by the time he came into the Luzhniki Stadium, winning by 62secs.
"It's surreal, it's just a great feeling," he said. "When I came into the stadium it just felt like an out of body experience. It's hard to take it all in at the moment. I'm delighted.
"Coming into the stadium I felt as if I was watching myself on the outside, looking at myself on the big screen and thinking, 'This fella looks good'."
Victory earned Heffernan his first major medal after years of near misses, including fourth-placed finishes over 20km and 50km at the 2010 European Championships in Barcelona.
He added: "I knew I was motivated. People go on about medals, for the last 11 years I've been motivated and challenging for a medal. For some reason or other I hadn't won one.
"I was prepared for everything coming into it. I stayed thoroughly motivated this year after London when a lot of people take their foot off the gas.
"I was very conscious of training hard and I had to be more motivated, because there was less hype for the World Champs. I was prepared for that mentally."
Australia's Jared Tallent took the bronze, with Heffernan's compatriot Brendan Boyce finishing 25th in a new personal best of 3:54.24.