Bob and Mike Bryan beat Dominic Inglot and Colin Fleming 6-2, 6-3, 3-6, 6-1 to cut Britain's lead over the United States to 2-1 in the first round of the Davis Cup on Saturday.
The twins breezed through the fourth set and won the match on a smash by Bob.
The tie will be decided on Sunday in reverse singles, when Wimbledon winner Andy Murray of Britain faces Sam Querrey and James Ward of Britain faces Donald Young.
Murray won the opening singles in straight sets against Young on Friday while Ward rallied to beat Querrey in five sets at Petco Park, the downtown home of baseball's San Diego Padres.
With Britain leading 2-0 entering Saturday, captain Leon Smith replaced Murray with Inglot for doubles.
The Bryans broke Inglot's serve in the second game of the first set and broke Fleming's serve to win the set.
The Bryans didn't face a break point until the sixth game of the third set. Fleming hit a backhander down the line to win the game for a 4-2 lead for the British. The teams held serve and the British won the set when Inglot had two straight aces in the ninth game.