By Tony Jimenez TROON, Scotland (Reuters) - Phil Mickelson came agonizingly close to shooting the first-ever 62 in a major championship as he stormed into the lead in the first round of the British Open on Thursday. The five-times major winner took full advantage of a calm, sunny day on the west coast of Scotland by reeling off eight birdies in a remarkable burst of scoring. History beckoned for Mickelson when he played a sumptuous approach to 15 feet at the 18th hole and the American held his head in his hands in stunned disbelief when the putt lipped out. More...