The Austrian, the first man down the Vertigine piste, pipped Germany's Andreas Sander by 0.01 seconds to add to Super-G gold in Cortina.
Vincent Kriechmayr was unbeatable on the brand-new Vertigine race piste in Cortina d'Ampezzo to win downhill gold at the FIS Alpine World Ski Championships on Sunday (14 February), completing the speed double.
Having won the Super-G on Thursday, the Austrian came into the race full of confidence. He picked bib number one, becoming the first man to race a downhill on the Vertigine in competition, and dominated in clear conditions with hard, grippy snow.
With last year's World Cup Finals (which should have served as a test event for the piste) cancelled, the field only had two training runs earlier this week to get used to the 2610m-long course, with its average slope of 31 per cent.
Kriechmayr, who won downhill bronze at the last world championships in Åre, skied a clean line and was only nearly caught out by a tricky control gate on the Canalone traverse section of the course, which would later prove the undoing of team-mate and another race favourite Matthias Mayer.
The 29-year-old crossed the line in one minute, 37.79 seconds – just one-hundredth of a second, or an advantage of just 27 cm, ahead of silver medallist Andreas Sander of Germany, who wore bib number two.
Switzerland's Beat Feuz, winner of the double downhills in Kitzbühel last month, was third, 0.18 seconds behind Kriechmayr.
With his win, Kriechmayr became the first Austrian men's downhill world champion in 18 years since Michael Walchhofer accomplished it in 2003. He also became just the third man, after Hermann Maier (1999) and Bode Miller (2005) to do the speed double in the same year.
There was also a remarkable escape from a serious crash for France's Maxence Muzaton, who caught an edge and was flipped 180 degrees before somehow landing on his skis going backwards; Germany's Romed Baumann finished the race but crashed into the advertising barriers and padding in the finish area, suffering facial bleeding.
"Hermann Maier is an Austrian legend and Bode Miller is a legend too, of course," Kriechmayr told FIS after his run.
"It was a really special race today, with bib number one it wasn't so easy and it looks like it was good enough for the victory today. An amazing race."
Speaking to Eurosport, he added: "It's pretty amazing, it was a difficult race. It was not perfect, I lost a lot of time on the last part of the race but I was pretty fast on the middle part. It was good enough, and that's it.
"Yes, of course I had my medal, I already had a medal and I wanted to show my best today.
"I always was a fan of these two guys but to be on the same step as them is amazing," he said of comparisons to Maier and Miller.
Silver medallist Sander, who continued Germany's run of silver medals at the Championships, told Eurosport: "Just one-hundredth, I saw it and I was like 'uh-oh, that could be... hopefully it's not for a medal'.
"I saw the time, it was really fast, 1:37, and then I thought maybe it was a good one.
"I was feeling good, I was really in shape and felt good. I felt like maybe I could do it and cause a surprise. I felt it at the start. In the end, super happy."