Scottish curling skip Muirhead defeated Sweden's Margaretha Sigfridsson in the final of the prestigious Players' Championship in Toronto.
Sigfridsson was looking to avenge defeat in the World Championship final last month but Muirhead's rink again got their tactics spot on, emerging 8-5 winners to also claim the Grand Slam title, an elite series of men's and women's curling events which are part of the World Curling Tour.
And the victory also secured a number of firsts and another big morale boost as attention turns to next year's Winter Olympics in Sochi.
"It feels great to be the first European team to win a Grand Slam as well as the first team to win a Players' Championship after winning the World Championship, capping off an unreal season for Team Muirhead," said Muirhead, whose rink banked $35,500 for their efforts.
"We've trained so hard and worked so hard, and to know it all paid off is a relief."