The Scottish skip, a silver medallist three years ago, recorded victories over Russia and the USA to conclude the round robin stages with an impressive 10 wins from 11 games.
And her rink will now face Margaretha Sigfridsson's Sweden, the only team they've lost to this week, for a place in Sunday's gold medal match.
"The first job was to qualify for the 1-2 play off and that's what we've done. That was another solid game," said Muirhead, after defeating the USA 8-4.
"We didn't want to come out and have a slack game, so it was good to keep strong and finish dominantly."
Muirhead credited coach David Hay for improving her rinks' mental attitude and also claimed a punishing new fitness routine was reaping dividends.
"We’re all ten times fitter than we were last year, and that’s made a huge impact, the fitter I am the more mentally fit I am," she added.