By Patrick Johnston SINGAPORE, Jan 29 (Reuters) - South Korean Song Young-han soared to the Singapore Open lead after a sparkling eight-under-par 63 on Friday as world number one Jordan Spieth had his second round charge halted by more inclement weather. The 22-year-old American, the headline act of the Japan Golf Tour and Asian Tour's season opening event, was level par after six holes of his round on Friday when rain then lightning warnings forced the players from the Sentosa Golf Course. Spieth will resume on Friday with a testing birdie putt after being caught out by the changing weather on the seventh. More...