Great Britain may be perennial underachievers in world tennis but when it comes to the sport's premier team competition Wimbledon's host nation continues to punch over its weight. In the city of his birth an emotional Andy Murray carried his side into the last eight of the World Group knockout by fending off a ferocious challenge from American giant John Isner to secure a 3-2 victory. To the deafening acclaim of Glasgow's Emirates Arena the former SW19 champion survived a tough opening set to win 7-6 6-3 7-6 against the world number 20 to wrap up the tie with his second point. Andy Murray celebrates extravagantly after winning the first set on a tie break to leave Great Britain just two sets from the quarter-finals . The British No 1 was spurred on by the Glasgow crowd to secure a 3-1 win over the USA and book a quarter-final against France . Murray is forced to stretch to reach a backhand as John Isner put in a much better performance on Sunday in the Davis Cup . Against one of the best servers ever seen in tennis Murray's coolness in the tiebreaks was the key, as was his ability to save seven break points in the opening set. 'It was a great win for the team, everyone played their part,' said Murray. 'Togetherness was a key, everyone was pulling in the same direction. 'I managed to find a way through the first set. I was over complicating my service games at first and he was going for broke on the first point of every rally. The huge American showed aggression in a first set where he forced seven break points on the Murray serve, but couldn't take any of them . Murray was well supported by a partisan Glasgow crowd as he sought to book Great Britain's place in the Davis Cup quarter finals . Isner plays a forehand on the run as the USA's top player started fast in a game his country needed to win to stay alive in the match . Murray was not at his best early on, but rallied to take the first set on a tie break after saving three set points . GB are through to the elite World Group quarter finals for the second year in succession and now face a home tie against France – 3-0 winners over Germany - immediately after Wimbledon in July. If on grass it is likely to be held somewhere like Eastbourne or Nottingham, but if they opted for an indoor court it would likely come back to Scotland, as the fans here have been outstanding in this match. 'If everyone plays to their abilities we have the chance to win more matches. We don't have huge margin for error but if Wardy (James Ward) plays like this we have a chance, although France have huge strength in depth.' This match turned out to be remarkably similar to last year's World Group first round against the same opponents: Ward upset the American number one on the first day, before the Bryans pulled the doubles point back for the USA and then Murray finished it off with his second singles win. Great Britain captain Leon Smith and his staff celebrate as their talisman Murray wins a crucial point against the American Isner . Isner looks stunned during a tough first set where he played plenty of good tennis and earned seven break points, but couldn't break through . Isner looked to have put everything he had into the opener, and looked exhausted after losing the first-set breaker . Isner once beat Roger Federer in an away match against Switzerland so is no shrinking violet in the cauldron of Davis Cup competition and British Captain Leon Smith – low profile but with an excellent record in this job – knew that he could be a danger. That did not take long to be confirmed and the 6' 10' American, revelling in his underdog status unlike on Friday against Ward, came out swinging. A more under pressure was a little hesitant and he had to fend off seven break points in total before the tiebreak, once at 1-2, three times at 3-4 and three more times at 4-5. Isner twice took enormous forehand cuts and shaky second serves and will have been massively frustrated not to have taken the lead. Smith whispers some advice and encouragement into his player's ear between games as Murray booked Britain's place in the last eight . Murray continued to show his emotion as he began to find his best form in front of a raucous crowd in Glasgow . Murray's serve had come under pressure in the first set, but as Isner tired the British No 1 became more secure . His serve was as potent as ever but, crucially, he double faulted at the start of the tiebreak and after that Murray clung on to his lead to clinch it 7-4, a massive psychological blow as he had been outplayed. The nerves of him and another hugely committed crowd were eased by that, especially as Isner needed to play nearly five hours on Friday. A brilliant backhand lob at 3-2 in the second set secured the key break there, but to give Isner his due he kept fighting to take it to second tiebreak. Murray went ahead 6-2 and then finally finished it with a swinging serve ace at 6-4 to complete his weekend's work. Murray stretches for a forehand as he wore down his opponent before pulling out an array of stunning passing shots in the later sets . Isner had played five sets in his defeat to James Ward on Friday, and the effort caught up with him after a brave first set on Sunday . Isner is consoled by his USA Davis Cup captain Jim Courier as he struggles to cope with Murray's athleticism in Glasgow .
Andy Murray takes first set on a tie-break after saving seven break points . British No 1 breaks John Isner's serve for the first time in sixth game of second set, takes set 6-3 . Murray wins third set tie break to seal 3-2 victory in the tie . Great Britain will face France at home in July in quarter-finals .