Giovanni De Gennaro grabs gold for Italy in men's kayak slalom
French teenager Titouan Castryck finished two-tenths of a second behind to take silver in his first Olympics, with Spain's Pau Echaniz claiming bronze.
"I think this is still a dream. I don't know and I can't believe it. I just want to see my family," De Gennaro told reporters.
Echaniz looked good as he opened proceedings, setting a time of 88.87 seconds that forced the rest of the field to dig deep, and despite a slew of Olympic medal winners coming in his wake, only two men proved able to beat his time.
The competition caught fire when Italian world number two De Gennaro went out fifth and wasted no time attacking, the crowd roaring its approval as he pivoted through the upstream gate at the halfway point before sprinting cleanly through the rest of the course to take the lead.
Jiri Prskavec’s time as Olympic champion effectively ended when he collected the second of two two-second penalties by clipping gate 16, with the Czech finishing a disappointing eighth.
Tokyo silver medallist Jakub Grigar of Slovakia suffered a similar fate, slowing up considerably over the second half of the course as his chance of another Olympic medal evaporated.
With only three racers left, the 19-year-old Castryck brought the home supporters to their feet as they roared their approval, waving their flags and increasing the volume with every successful move he made.
An error at gate 17 robbed him of his momentum, however, and his run was only good enough for second place.
Germany's Noah Hegge struck the poles of gate 16 with the bow of his boat to end his challenge, leaving only 2016 champion Joe Clarke of Britain.
He was also unable to match the speed and skill of De Gennaro, and the Italian celebrated wildly when the Briton crossed the line more than a second and a half off the pace.
"It means everything. Everybody was on my side. I had a lot of people supporting me, especially after Tokyo when I couldn't make my run. Today I'm just happy that I could be myself and with this result, it's just a dream come true," De Gennaro said.