The 20-year-old led from start to finish in the final to take the title ahead of Canada's world number one Dominique Maltais.
“It's simple, it's just for luck. It's a lucky moustache but this one is special. Because of this special day it's in the national colours,” said Samkova, after topping the podium.
“It started in 2011 at the World Championships in La Molina. That was my first world championships and I painted a moustache and I was fifth,” she added.
“It was my best result in that time so I decided to paint it all the time, and it gives me luck.”
France's Chloe Trespeuch took bronze after avoiding a late collision between Michela Moioli of Italy and Alexandra Jekova of Bulgaria.
Samkova was in a class of her own throughout the day, finishing top of the pile in the morning's time-trial runs to decide seedings for the main competition.
She then led from start to finish in all three rounds.
“My coach [Jakub Flejsar] told me the best thing I can do is just be in front of them,” explained the Czech.
Flejsar commented that he was always confident that his charge could prevail.
“I thought she's going to win because she's the best of the girls,” he said. “It was more about the pressure on her. I knew that if she didn't make any mistakes, she'd get it.
“She's the best in sucking down the jumps and pushing the rollers. She's got fast legs and good timing,” he added.
Vancouver gold medallist Maelle Ricker of Canada exited the competition in the quarter-finals as she tried to take a tight inside line on a bend in an attempt to make up a couple of positions as she was running outside the qualifying spots.
And there was further disappointment for one of her fellow favourite in the semi-finals, as American Lindsey Jacobellis, the silver medallist at Turin 2006, wiped out as she was leading by a large margin.
Meanwhile Maltais, expertly swerved past the falling Jacobellis to make it to the final, and eventually claim silver. “I knew Lindsey was going really high in that bank and unfortunately she crashed,” explained the Canadian rider.
“I was going for the inside line when I saw her starting to slide down, which is where my line was. I knew it was a case of: go for it and see what happens. That's snowboard cross!”