(Reuters) - Japan's Hideki Matsuyama turned in his first flawless round of the WGC-HSBC Champions on Saturday to head into the final day's play with a three-shot lead over reigning champion Russell Knox. Starting the day with a three-stroke cushion after 19 birdies over the first two rounds, Matsuyama was again in impeccable form at the Sheshan International Golf Club, carding a four-under-par 68 to end the day 17-under for the tournament. "But today, when you're in a position to win, playing smart and making no bogeys was very satisfying to me ... I think the key for tomorrow's round will be not making any bogeys." Knox, who won on debut last year, also carded 68, with American Daniel Berger a shot behind him in third place on 13-under after mixing eight birdies and three bogeys in his 67.
