KAWAGOE, Japan, July 31 (Reuters) - A slow-burning Olympic golf tournament roared to life on Saturday as American Xander Schauffele fought off attacks on all fronts to cling to a one-shot lead over home hero Hideki Matsuyama heading into the final round. The stage is set for a battle royale at Kasumigaseki Country Club on Sunday, with nine players within four strokes of Schauffele, including former world number one Rory McIlroy. Overnight leader by a stroke, Schauffele was stalked relentlessly by playing partners Matsuyama and Mexican Carlos Ortiz but he broke clear with a birdie on the 18th to card 68 for a 14-under total of 199. "It’s been a fun week. I’m in a good position heading into tomorrow," Schauffele told reporters after landing a sublime nine-iron three foot from the 18th pin for a tap-in putt. "Today could have gotten away from me if I had a bad attitude or what-not, but I kind of hung tough. I fell back on certain parts of my game to hold me tight." Matsuyama, who battled a recent COVID-19 illness, struggled off the tee through his four-under 67 but his brilliant short game saved him, and he drained a clutch putt for par on 18 to keep the heat on Schauffele. Japan"s first major winner said he felt his nerves were not much different to his experience at the Masters, where he held a four-shot lead overnight before claiming a one-stroke win. "The fact that the third place is still celebrated as well as second (at the Olympics), there’s a nice thing waiting for you even if you"re third," he said. "So I’m not sure what my motivation going into tomorrow will be but I’m going to focus on playing good golf." Ortiz (69) is a shot further back in the bronze medal position with Briton Paul Casey (66), the Mexican ruing a bogey on a scrappy last hole where he lipped out on a short par putt. McIlroy enjoyed a solid day out with Ireland team mate Shane Lowry in his group, shooting a 67 to be three strokes shy of Schauffele on 11-under. "I’ve got a great chance heading into tomorrow," said the four-times major winner. "It’s a bit of a packed leaderboard, so all to play for. It’s going to be brilliant." Britain are right in the medals mix, with Casey"s team mate Tommy Fleetwood soaring up the leaderboard after an inspired 64. Fleetwood racked up seven birdies in nine holes from the sixth to the 14th and is four behind Schauffele on 10-under with Lowry (68). Australia"s Cameron Smith also raised his game on "moving day", shooting a 66 to be nine-under, but British Open champion Collin Morikawa"s hopes of winning gold for Team USA faded. The American rallied with a 67 to finish seven-under but he will need everything to go right on Sunday to reel in a seven-stroke deficit to his team mate Schauffele.