They were on their feet once more moments later when Murray levelled the match at one set all but Argentina’s captain Daniel Orsanic was furious at premature noise from the British fans.Several breaks of serve followed in the third set before another controversial call. At a crucial point, Murray believed the point had been stopped only for the umpire to allow the game to continue and hand Argentina a 5-3 lead. Murray produced another stunning lob which sparked a memorable comeback to take the set on a tie break.Any thoughts of an easy ride from there on in were dispelled as the world number 64 produced a beautiful drop volley to take the fourth 6-3.Both players were battling fatigue but still managed to produce moments of genius with del Potro chasing down a smash to unleash a glorious forehand passing shot and break for a 4-3 lead.And it proved to be enough as del Potro served an ace to secure an epic victory. Andy Murray endured the longest match of his career as he lost a five-set thriller to Juan Martin del Potro in the Davis Cup.The world number two, who was missing his grandfather’s funeral to take part in the match, dug deep but was unable to overcome his opponent as Argentina took a 1-0 lead.Dunblane ace Murray played for over five hours before going down 6-4, 5-7, 6-7, 6-3, 6-4.The match started with Murray producing three outstanding lobs over the 6ft 6in Argentine but del Potro quickly found his rhythm. He made his move at 3-3 to take the initiative and duly claimed the opening set 6-4 with a fine service hold.Too many errors were coming from Murray’s backhand while del Potro’s thunderous ground strokes were being used to great effect.The world number two was having to work hard to remain in the match, digging deep to hold serve until the business end of the set. At 5-4 and 15-15 Murray chased down a lob before producing a stinging forehand on the turn to send the home crowd wild.