A net cord helps out Querrey with what was already a pretty good drop shot and at 15-15 he lines up another of those big off forehands, but misses the line and the game is gone moments later. The American really needs to take every half-chance that comes his way.

A swift love hold for Querrey gets a tentative round of "USA! USA! USA!" going in the stands.

We're back into the early routine of the match as Murray dominates all the baseline exchanges, exposing Querrey's lack of ability to move like the very best players. More eclectic brass bandery in the stands.

A backhand down the line, a fizzing forehand return, a badly mistimed Querrey forehand... Murray earns set point at 30-40 but cannot make the return, and a poor drop shot allows Querrey to get back in front as he takes the game.

Jeff Tarango
Former American tennis player on BBC Radio 5 live sports extra

"If they had an arm wrestle, Querrey would win. If they competed at bench-press I think Querrey would win. But Murray showed great resilience to win that first set."

A reflex volley and a forehand hooked down the line get Murray to 30-15, and he smashes away a short ball to take the game. Four sets down for the weekend, it's hard to know what Courier can say to Querrey at the changeover.

Allie:, external Think that could be it. Querrey played awesome and he still lost the set.

Katie B:, external Jim Courier looks more like Querrey's lawyer than his coach.

John Lloyd
Former British number one on BBC Red Button

"How will Querrey feel about that? He knows he has to win three more sets now, having lost to Murray in that first set having himself won a lot of points and hit a lot of winners."

Image source, Getty Images

Murray takes Britain to within two sets of a quarter-final place, and captain Leon Smith has teeth gritted and fist clenched as a tricky opening to the match is successfully negotiated. The court gets a watering before play resumes....

Querrey opens with a big serve, Murray responds with one of his own but then puts a forehand wide. Querrey swings away a drive-volley and Murray looks less than chuffed. A long rally follows, and Murray guides a backhand past the net-bound Querrey, but the American regains the mini-break with a backhand-forehand combination for 4-2... a change of ends and Querrey plays a shocker of a backhand, before failing to pick up a Murray slice and netting a forehand. A beautiful drop volley keeps the American's nose in front at 5-4 on serve... Querrey fails to take advantage of a second serve and Murray levels at 5-5...

Murray swings a serve out wide and it's set point... the Briton cannot put away a drive-volley and is forced back behind the baseline, but Querrey plays a desperate, desperate drop volley into the net with his opponent closer to the stands than the ball. It might take more then the 'Courier Crouch' to get him back into this one.

You know Querrey is confident when he's going for angled forehand drop shots, this one missing by the narrowest of margins, and Murray comes through an uncomfortable game to force the tie-break.

Not the best five minutes for Murray, who works an opening at 30-15 down only to dump a smash into the net. Querrey then digs a serve in at the body and suddenly he's one game from the set. Captain Courier chooses this moment to unleash 'the crouch' at the changeover.

It's hard going for Murray, who misses with a forehand at 30-30 and faces break point... Querrey leaps on a second serve, skipping around his backhand to fire a forehand into the corner. A good effort from the American, who is battling hard.

Querrey keeps the set alive with a terrific forehand winner from out wide, and the American bench are up on their feet. There seem to be a lot more of them today, and they're more animated. Super Bowl fever, maybe. Team GB, decked out in bright red, applaud their man as he strides out to serve for the set.

Zach Kingsbury:, external Murray will sweep Querrey under the clay.

Stephen Organ:, external I love Davis Cup so much - atmosphere is unreal.

Murray guides a drive-volley over for 30-0 and manages to keep the ball away from Querrey's forehand long enough to draw the backhand error for 40-15. An ace seals the game.

Ross Hutchins
British doubles player on BBC Red Button

"When you watch Andy Murray you might think he just plays the same game over and over again. Far from it. He plays with different height trajectories, target opponents' weaknesses, reads where they're going to serve on different occasions. There are so many variables in his mind at any one time, which is a knack very few players have."

Things are getting a bit lively at Petco Park. Murray responds by racing to 0-30, only for Querrey to get back to 30-30 with some positive intent. Murray then hammers a forehand winner after Querrey goes the wrong way with the court at his mercy and it's break point... but Murray pulls a forehand wide. The Briton swings a backhand past the American to earn a second break point... and Querrey just misses with a forehand, Murray helpfully circling the mark as he strides back to the chair.

Umpire Molina is down from his chair to check marks after each of the first three points, and Querrey comes off better from the interruptions by cracking a return to get to 0-30. For the first time, there's an air of hope to the home crowd's cheering. Murray belts a forehand winner and gives himself a "Come on!", but when he then finds the net it's 15-40 and two break points... a good second serve out wide is enough to see off the first, but Querrey fires a backhand cross-court winner on the second and he's back on level terms.

Tom Garry:, external Sitting down to watch British tennis history be made.

Steve Houghton:, external Why is Jim Courier wearing a suit? He looks like he's come straight from work...