Mouat has beaten Niklas Edin in eight of their last 10 meetings, and the Swede could not disturb that trend high in the Dolomites in northern Italy.
It continued the Scot’s recovery from his mixed doubles medal disappointment and leaves the Swedes – who lost their opener against the hosts and face another medal contender in Canada next – in a perilous position.
“All four of us were really shooting well,” Mouat told BBC Sport. “We’ve not trained together for a month so to come back and the flow to be where we want it to be is excellent.”
These two are arguably the best rinks in the competition, with the Canadians, Italians and Swiss also likely to be in the medal conversation, and this was a high-grade contest.
However, Mouat, Hammy McMillan, Bobby Lammie and Grant Hardie won the hammer – the right to throw last and, in theory, control the game – and dictated from there on.
Edin failed to pull off a high-tarriff double takeout in the first end, allowing Mouat to claim two points and establish a lead that the GB rink would keep throughout.
Missing became a theme for the feted Swedish skip, the 40-year-old repeatedly failing to ask the questions that Mouat posed. As a result, the British team led 4-1 at halfway, and eked that advantage out to 6-2 with three ends remaining.
Sweden needed something big but could only find something small. They were restricted to one in the eighth and Edin decided he had had enough, offering a hand to Mouat and ending this contest with two ends to spare.
“Everyone keeps reminding us they beat us in Beijing so we had that motivation,” Hardie told BBC Sport. “They had an off-day and we took advantage of that.”