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Asked if that is the best win of his career, Ward tells BBC Three: "It is. Sam's ranked pretty high. The one against Tursunov (Russia) was also a massive win for me. I hope to use it and push on from here. I love playing for my country and it shows in my performance."

So did he really believe he could win from a break down in the fourth? "I did. It's easy to say but I played him in the past and beat him in three sets. At one point he was serving unbelievable and I couldn't really get near him. I held serve from 0-40 and that was key. I started reading the serve a little bit better. It's just a great win. I dug in and gave myself a chance. In the end it worked."

John Lloyd
Former British number one on BBC TV

"It was gutsy. It shows you what Davis Cup is all about when someone like Ward comes up against a player of Querrey's class, and plays way above his ranking."

Ross Hutchins
British doubles player on BBC TV

"It was an incredible performance from Ward but he just hung in there so well. His best was incredible, and he's a Davis Cup player, he loves it."

Ward is in a bit of trouble again at 15-30 but gathers himself brilliantly to level at 30-30, and then steer a forehand into the corner for match point. The Briton keeps up the attack, forces a defensive lob.... and smacks away the smash! Easy as that. What a stunning effort from the Londoner. USA 0-2 GREAT BRITAIN.

Querrey is looking a bit ominous as he quickly moves to 40-15 but Ward sticks in there, gets back to deuce and the pressure tells as Querrey hands over yet another break. Ward will serve for the win of his life, and - almost - a quarter-final pace for Britain...

The first sign of nerves, and probably not the last. One of Ward's breaks disappears as the feet stop moving and Querrey gets lucky with a net cord on his second break point.

Ward is absolutely flying now, finding winners from all angles, and a couple of zingers take him to an eighth successive game and another break. Jim Courier is struggling to keep up the cool exterior as Querrey crumbles before him.

Ward brings his man into the net twice in succession and beats him both times, once with a fizzing backhand and once with a delicate lob. Murray and GB fitness trainer Matt Little is possibly the most pumped man out there, leading the cheer squad. Incredible stuff going on in San Diego right now...

Ward has all the energy out there at the moment and is dictating with his usually less-favoured forehand. He gets to 15-40, two break points... a big serve saves the first, but Ward steps in and hammers a backhand winner on the second. "Yessss!!!!!" screams Ward on the follow-through, and he's well and truly on a roll. Can he maintain it?

US captain Jim Courier chooses this moment to head off court, meanwhile Ward is firing on his forehand and holds to 15.

Catie Craig:, external Every time querrey looks like winning I get ready to head to bed. Then ward pulls this out the bag and I'm still on the sofa.

Jay McElhinney: , externalWhat a comeback! What a game of tennis! James Ward take a bow son!

SAM:, external Well there's my early night gone...Come aaaan Ward!!

John Lloyd
Former British number one on BBC TV

"Querrey had chances for the double break and didn't take them, and now the pressure is totally on him. He loses this set and he knows his team are basically out if it."

Some great defence gets Ward off to a good start and a dispirited Querrey then floats a backhand wide for 0-30. More scrambling and squash shots help Ward to 0-40 and three set points... Querrey saves the first with a good forehand, Ward puts one in the net on the second, a long rally follows, plenty of jousting.... and Querrey nets! We're heading for a fifth.

Ross Hutchins
British doubles player on BBC TV

"Leon will be telling him, 'Keep the ball in court, keep swinging and trust in your shots.'"

"Where's this noise come from?" asks Ross Hutchins on BBC Three as the atmosphere finally kicks in at Petco Park. Ward lets a 40-15 lead slip but battles through from deuce, and now Querrey must hold to keep the set alive.

Ward is pressing hard and gets himself a break point, only to blaze a return long. That prompts the Briton to think about smashing his racquet, but he resists the temptation and moments later plays a running forehand pass to set up another chance. This time, Querrey goes long and we're back on serve. Murray and the rest of the British team are on their feet as new life is breathed into day one.

More pressure on Ward at 15-30, and again he pulls it out with some good serving and a rasping backhand down the line.

Querrey holds in little over a minute as Courier stalks the tramlines.

A quick hold for Ward and the pressure is back on Querrey. Captain Leon Smith adopts the crouching approach to this changeover, like a teacher dealing with one of the more sensitive children. The brass band is squealing away - "I'm not sure I've ever heard music like this at a Davis Cup tie," muses John Lloyd on BBC Three.

As the floodlights go on at Petco Park, Ward suggests he might be sticking around. A sweeping forehand pass gets him to 15-30 and some heavy forehands into the corner earn the Briton his first break points of the match. Querrey reacts well, hitting a big, flat forehand winner of his own and then driving his opponent out wide and into an error. The American holds.