Andy Murray beat Sam Querrey in four sets on Sunday to send Great Britain into the quarter-finals of the Davis Cup for the first time since 1986.
Wimbledon champion Murray posted his second singles victory of the tie, downing Querrey 7-6 (7/5), 6-7 (3/7), 6-1, 6-3 to capture the needed third point in a 3-1 victory in the best-of-five match tie.
Britain had seized a commanding 2-0 lead on the opening day on Friday as 175th-ranked James Ward pulled off a remarkable comeback win over Querrey.
Ward won 10 of the last 11 games to grab the five-set triumph, after Murray had crushed Davis Cup newcomer Donald Young in straight sets.
Young was a late replacement in the US squad for injured John Isner.
The formidable doubles duo of Bob and Mike Bryan had kept the Americans alive with a doubles victory over Colin Fleming and Dominic Inglot on Saturday.
However, Querrey couldn't prevent Great Britain from posting their first Davis Cup win over the United States since 1935.
That winning British team was led by Fred Perry, putting Murray in Perry's footsteps again after the Scot's Wimbledon triumph last year made him the first British man to win at the All England Club since Perry in 1936.
While he delivered two of Great Britain's three points, Murray said Ward's magnificent rally against Querrey on Friday shouldn't be overlooked.
"It's obviously nice, you want to try and contribute as much as possible in these weeks," Murray said.
"James had a great win against Sam the first day to put us in that position and it was up to me today to try and close it out."
Murray, who had back surgery in September, needed two hours and 54 minutes to get past Querrey on the red clay court at Petco Park - home of Major League Baseball's San Diego Padres.
Murray and Querrey split the first two closely contested sets. Murray had a chance to serve out the first in the 10th game but was broken for the second time and they went to the decider.
In the second, neither man managed to gain a service break and Querrey took the tiebreaker, but he was unable to build on that momentum as Murray broke him twice en route to a 3-0 lead in the third frame.
Murray earned the break he needed in the sixth game of the fourth set, but had to fend off two break points in the final game before sealing the match when Querrey sent a service return out.
Murray let loose with a yell of delight, then celebrated with his teammates. The scheduled fifth rubber between Young and Ward was scrapped.
In the quarter-finals Britain will face Italy, who sealed a 3-1 victory over Argentina in Mar del Plata on Sunday.
"This is the first time I've been involved in Davis Cup that we've had a chance of winning the competition," Murray said. "It's obviously going to be extremely tough but we have a great team spirit."
The United States will face a playoff to remain in the elite World Group.