Great Britain's women equalled an Olympic record score when they thrashed the United States 12-3 in six ends in Sochi on Tuesday.
Eve Muirhead's team bounced back from an opening game defeat to Sweden by scoring seven in one end, which itself has never happened in an Olympic Games before.
Earlier, Great Britain's men recorded a dramatic win over Germany, overhauling them 7-6, when they looked destined for defeat.
Germany only needed to push David Murdoch's stone out of the house scoring zone in the final end.
But Germany's Felix Schulze got his line wrong as Britain claimed their second win in three round-robin matches.
A relieved Murdoch, who has finished fourth and fifth at the Games, said afterwards: "I think it's about time I had Olympic luck. I've not had much in my previous eight years.
"We are pretty pumped up after winning that one and we need to have that attitude for the rest of the games. We can't start lackadaisical, we need to come in pumped up and get on top of things. We are winning hammer every game and not really capitalising."
And regarding the last-gasp win, he added: "I think we're very good with pressure that way and being very accurate. What we need to do is take that into all ends and we'll create a few more chances."
Muirhead was delighted with her performance after a disappointing opening day for the medal favourites.
She said: "There were a few areas we struggled on yesterday but we were determined to get off to a good start today and gave them no chance."
GB women face medal rivals Canada at 10:00 GMT on Wednesday, while the men face Switzerland at 15:00 GMT.