The skier from Rosemere, Que., used a double twisting back flip to defeat Canadian teammate Mikael Kingsbury in the final for his second gold medal in as many days.
"Every time it's super tight between us and could go either way," said Bilodeau, who also beat Kingsbury in the moguls final on Friday. "It's a trick that's never done in duals, and I didn't even train it because I wanted to keep it a secret, but I'm pretty confident with that jump so it was a gamble to do it, but it paid off."
Despite finishing second, Kingsbury — the moguls world champ from Deux-Montagne, Que. — only needs three points from the season-ending dual moguls event in Sierra Nevada, Spain, next week to win the overall crown.
"Against (Bilodeau) it's never easy, so I pushed to the max," he said. "Alex for sure did a bigger air on the top, but I got him by half a second in speed."
Bilodeau says both he and Kingsbury benefit from training with each, but it's all business once they're in competition.
"When we're on the hill ... I don't feel like he's a teammate," Bilodeau said. "He's an opponent — whether he's from Zimbabwe or Canada — and that's how he feels also."
Bradley Wilson of the United States beat Per Spett of Sweden for third.
Hannah Kearney of the U.S. defeated Yulia Galysheva of Kazakstan to win the women's dual moguls final.
Montreal's Chloe Dufour-Lapointe took third ahead of American Heather McPhie, the moguls winner the previous day.
With one event left, Kearney leads the women's standings by 60 points from Dufour-Lapointe, and 64 over McPhie.
Meanwhile, Alex Fiva of Switzerland held off home favourite Viktor Oehling Norberg to win the first of the weekend's two skicross races.
Jean Frederic Chapuis of France, who won the world championship last weekend in Voss, Norway, was third. Montreal's Chris Del Bosco finished eighth.
Fiva extended his lead in skicross World Cup to 574 points, 140 points better than second-placed teammate Armin Niederer, with two events left.
Anna Woerner of Germany won the women's race. Marielle Thompson of Whistler, B.C., finished fifth after her ski popped off in the semifinals, while Georgia Simmerling of West Vancouver, B.C., was seventh.
World champion Fanny Smith of Switzerland didn't compete, but still leads the season standings by 34 points from Ophelie David of France.Suggest a correction