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 heading into the final round.
Overnight leader by a stroke, Schauffele was stalked relentlessly by playing partners Hideki Matsuyama and Carlos Ortiz at Kasumigaseki Country Club but he broke clear with a birdie on the 18th to card 68 for a 14-under total of 199.
A stroke behind Schauffele, Japan's Matsuyama drained a putt for par on the 18th to finish with a four-under 67, while Mexico's Ortiz (69) held the bronze medal position alongside Great Britain's Paul Casey (66) after a bogey on the last.
The stage is set for an epic battle in Sunday's final round, with nine players within four strokes of Schauffele, including former world No 1 Rory McIlroy.
McIlroy enjoyed a day out with Ireland team-mate Shane Lowry, shooting a 67 to finish three strokes behind Schauffele on 11-under.
Britain are prominent at the top of the leaderboard, with Casey's team-mate Tommy Fleetwood soaring into contention 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 alongside Lowry (68).
Australia's Cameron Smith also raised his game on "moving day", shooting a 66 to be nine-under, but 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.