By Patrick Johnston SINGAPORE (Reuters) - World number one Jordan Spieth and South Korean Song Young-han will return on Monday to complete their battle for the Singapore Open title after stormy weather agonizingly stopped play at the climax of their final rounds. Song had a 10-foot putt on the 16th green to stay at 12-under-par, while Spieth was presiding over a five-foot birdie effort on the last to sign for an 11-under total when play was halted just before 3 p.m. (0700 GMT) because of inclement weather. "Assuming I make that putt on 18 that is going to put some pressure on," Spieth told reporters after shooting four-under for his 17 holes. More...