(Adds detail, quotes) Jan 9 (Reuters) - Jordan Spieth closed in on his seventh PGA Tour victory as he hit an exquisite three-iron to eagle the par-five last and seize a five-stroke lead after the third round of the Hyundai Tournament of Champions in Hawaii on Saturday. "I just tried to put a smooth swing on it," Spieth, 22, told Golf Channel about his three-iron approach at the last. Spieth, who would match Tiger Woods with a seventh PGA win before the age of 23 should he triumph on Sunday, was delighted to rebound from a poor stretch of holes from the short eighth, which he bogeyed after missing the green. More...