Wins for Murray over Donald Young and, thrillingly, James Ward in five sets over Sam Querrey on Friday put the visiting British ahead in the World Group tie and requiring only one more point for a famous victory in San Diego. Murray can seal their place in the quarter-finals by beating Querrey in the opening match today. A win, should the Scot pull it off, would seal Britain's first win over the US since 1935.
Murray had been scheduled to line up with Colin Fleming against the best doubles pairing in the world - Bob and Mike Bryan - yesterday, but captain Leon Smith opted to rest the British No 1, deciding to keep him as fresh as possible for today's crunch game.
Davis Cup debutant Dom Inglot joined Fleming, but though they were able to win one set, they were not able to pull of another shock, going down 6-2, 6-3, 3-6, 6-1.
While Murray showed no ill effects from his Australian Open exertions against Young, racing to a 6-1, 6-2, 6-3, win, world No 175 Ward's triumph was even more impressive, as he battled for over three hours, winning 10 of the last 11 games, on his way to a 1-6, 7-6 (7/3), 3-6, 6-4, 6-1, victory.
The big-serving Querrey, ranked 49th, was the clear favourite, but the English player justified the faith shown in him by Smith to record a famous success.
Ward said: "I love playing Davis Cup, I love playing for my country and that shows in my performances. It's such a great win. I played well, dug in and gave myself a chance and in the end it worked."
Asked how he had managed to claw his way back from two sets to one down and trailing 4-2 in the fourth, Ward replied: "I'm not quite sure at the moment. In the third [set], I started reading it a little bit better, he was going to my backhand quite a lot on every first serve. So I started to stand back a little bit further to give myself a little more time."