Calgary's Humphries and Valios of Zenon Park, Sask., finished two runs on the Utah Olympic Park course in a combined time of one minute 39.49 seconds, edging a pair of sleds from Germany.
The pair wore fake, drawn-on moustaches to support cancer awareness during the World Cup bobsled races Friday.
"You've got to have fun out there," said Humphries, who has won five straight World Cup events dating to last season.
Last year she had a different brakeman. Teaming with Valios hasn't meant a drop-off.
"Chelsea has tons of potential," Humphries said. "It's real exciting as we get closer and closer to Sochi. But I'm fairly new. I still make mistakes, so I'm trying to get as consistent as possible."
Sandra Kiriasis and Franziska Bertels of Germany took silver in 1:39.77, while teammates Cathleen Martini and Stephanie Schneider were third in 1:39.81.
Americans Jamie Greubel and Katie Eberling were fourth at 1:39.88, while teammates Jazmine Fenlator and Emily Azevedo were fifth in 1:39.99.
Former track star Aja Evans pushed USA 2 sled to an eighth-place finish. In the process, she broke the start record on the Park City course, teaming with Elana Kamphuis
Last week she teamed with Greubel to break the start record in Lake Placid, N.Y., at the World Cup opener.
"Aza and Elana just killed it today," Humphries said. "They made all of us in the start house a little bit scared."
The Americans took silver and bronze a week ago, but coaches continue to switch out brakemen as they try to figure out which combinations are best.
With former track and volleyball athletes in the mix, it's made for an interesting show.
"I think it's great for the sport," Humphries said. "They've got experience and young guns that are up and coming. I can't control what anybody else does. All I know is I got a brand-new brakeman and we're going to work as hard as can to be on top."
Next up is Whistler, B.C., where Humphries won her Olympic gold.
"It's a great atmosphere," she said. "We always get tons of support and its where I won my Olympic gold, so deep down it's special."