Defeat not tweet for Murray

BRITAIN&rsquo;S Andy Murray was cruelly knocked out of the ATP World Tour Finals amid farcical scenes last night despite winning his final round-robin match against Spain&rsquo;s Fernando Verdasco.<br /><br />US Open champion Juan Martin del Potro&rsquo;s shock three-set win over world No1 Roger Federer took the pair of them through and sent Murray crashing at the first hurdle.<br /><br />But the convoluted qualification system baffled even the players, with Murray posting on micro-blogging site Twitter just after Del Potro&rsquo;s win: &ldquo;Anyone know what&rsquo;s going on?? I think I&rsquo;m audi but the rules aren&rsquo;t worded too well.&rdquo;<br /><br />Murray had earlier beaten Verdasco 6-4, 6-7 (4-7), 7-6 in an epic afternoon match to take his total to four points from three Group A clashes at London&rsquo;s O2 Arena.<br /><br />But the Scot faced a nervous wait as Del Potro recovered from a set down to repeat his famous US Open final triumph over the Swiss 15-time Grand Slam winner 6-2, 6-7 (5-7), 6-3.<br /><br />That left three players &ndash; Del Potro, Murray and Federer &ndash; tied on four points, but the home favourite was eliminated on game win percentage. Excruciatingly for Murray, he would have qualified if Federer had won, if Del Potro had won in straight sets, or if Federer had won a fourth game in the deciding set.<br /><br />The Argentine&rsquo;s 45 games won and 43 lost was superior to Murray&rsquo;s 44-43 record, and he celebrated by embracing his friend Carlos Tevez, the Manchester City footballer, at courtside to watch his countryman.<br /><br />Del Potro, however, seemed oblivious to his victory immediately afterwards, sitting on his chair shrugging his shoulders while the figures were calculated. More than 10 minutes after the match, governing body the ATP confirmed Murray was out.