Britain's Jennifer Dodds and Bruce Mouat, the 2021 world champions, clinched a 7-4 win over Sweden's Rasmus and Isabella Wranaa in the morning session, before returning to the ice hours later to crush Koreans Jeong Yeong-seok and Kim Seon-yeong 8-2.
The two wins cemented Britain's position at the top of the round-robin standings, having won all five of their games so far.
At the Beijing Games in 2022, Sweden's Almida de Val and Oskar Eriksson progressed to the semi-finals with five wins out of their nine matches, but Mouat said that number might not be enough to ensure qualification this time around.
"Last time was crazy, everyone was beating everyone, whereas this time it seems like everything's gone by what the odds might suggest," he added.
"We're probably looking at making sure we get to six wins, that is probably going to guarantee it, but with a lot of the top teams beating each other, it might even be tough to get through on 6-3."
US, Italy also win twice
The United States, the only other unbeaten team in the competition after three days of action, also claimed two wins on Friday.
Korey Dropkin and Cory Thiesse began by beating neighbours Canada 7-5 in a nail-biting encounter in which momentum swung wildly before a perfectly timed powerplay and a clutch shot from Thiesse sealed the victory in front of rapper Snoop Dogg.
The Americans then followed it up with an 8-1 win over Czechs Julie Zelingrova and Vit Chabicovsky.
Italy's Stefania Constantini and Amos Mosaner, who saw their unbeaten run ended by Canada on Thursday, recorded a massive 12-4 win over Switzerland in just six ends, before holding off Estonia to grab a 7-4 victory.
"After the loss yesterday, it was good to come back this morning and then this afternoon, we had a good day with two wins on board," Mosaner said.
"We are pretty happy about our performance, but we can still adjust some things."
Norway's two-time Olympic medallists Kristin Skaslien and Magnus Nedregotten breathed life back into their campaign, beating Sweden 9-0.
The Norwegian duo, who are bidding to add a third Olympic medal to their collection, had lost their opening three games of the competition.
Teams play nine matches in the round-robin stage, which continues on Saturday at the Cortina Olympic Curling Centre, with the top four advancing to the semi-finals next week.