|Davis Cup: Great Britain v United States|
|Venue: Emirates Arena, Glasgow Dates: 6-8 March|
|Coverage: Live on BBC TV, BBC Radio 5 live sports extra, Red Button, the BBC Sport website, mobile, the BBC Sport app and Connected TV.|
Britain still need a point to reach the Davis Cup quarter-finals after Jamie Murray and Dom Inglot lost a thrilling five-set doubles match to American world number ones Bob and Mike Bryan.
The Bryans won 6-3 6-2 3-6 6-7 (8-10) 9-7 in three hours and 37 minutes.
Britain will now head into the final day of the best-of-five World Group tie in Glasgow with a 2-1 advantage.
Andy Murray will hope to clinch the deciding point against John Isner in Sunday's first singles (13:00 GMT).
Isner lost 6-7 (5-7) 5-7 6-3 7-6 (7-3) 15-13 to Ward on Friday in a marathon match lasting almost five hours.
US captain Jim Courier said: "He feels good today and knows he has a big match ahead of him."
Should Isner win, it will come down to a decider between James Ward and Donald Young.
The prize on offer for the British team is a home quarter-final against France in July.
Scot Murray and Englishman Inglot ran the world's best doubles team desperately close in front of a raucous 7,700 spectators at the Emirates Arena, as they sought to seal the tie on day two.
"It was brilliant, definitely the best atmosphere I've played in in my life," Murray told BBC Sport.
"We did so well to come back and fought so hard. It's a shame we came up just short in the end but it was a brilliant experience."
Inglot added: "The energy that the crowd brought is something I will always remember.
"It was probably the most enjoyable experience I've ever had, to play in front of such a passionate crowd."
After losing the first two sets in under an hour, with the Murray serve broken four times, the British pair grew in confidence and understanding.
It was their first match together since they were juniors 12 years ago, and with Inglot's huge serve proving unbreakable all afternoon they forced the Bryans to win in five sets for the first time in the Davis Cup.
Captain Leon Smith opted not to risk drafting Andy Murray in for the doubles, leaving the British number one among the courtside support team.
He was as animated as the rest of the crowd as his brother and Inglot launched a remarkable fightback, grabbing the momentum by breaking serve in a dramatic fourth game of the third set.
Three break points were saved in a gripping fourth set, with Murray now more solid on serve, and the home side prevailed in a dramatic tie-break after Inglot saved a match point with a backhand return.
The Bryan brothers had lost the only two five-set matches they had played in the Davis Cup but they showed their class in the decider.
Inglot had played superbly throughout but with Murray serving at 7-7, the Englishman played a loose game at the net and the Bryans capitalised to grab the decisive break.
"We were telling each other 'let's erase all that pain' and this was a great way to do it - to win an emotional match," said Mike Bryan.
"Those guys didn't give us an inch all day. All credit to them, we had to bring our best stuff to win."