World No 1 Brooks Koepka has his work cut out if he is to win the Dunlop Phoenix Tournament for a third year in a row after falling five strokes behind leader Mikumu Horikawa during the third round in Miyazaki on Saturday.
's Horikawa will take a two-shot lead into the final round at Phoenix Country Club after firing seven birdies with a single bogey in a six-under-par 65 to move to 12-under 201 for the tournament after 54 holes.
Australian Brendan Jones and Japan's Shugo Imahira also shot 65s for a share of second on 10-under with South Korean Park Sang-hyun alone in fourth a further shot back after shooting a 68 for the third day in a row.
Koepka started the day three shots off the pace after landing three late birdies on Friday and looked to have ignited his round when he nailed an eagle putt at his fourth hole, a par five.
The American stalled when he gave back the shots with a double bogey at the next hole, however, and two more birdies over the back nine left him with a 69 to stand in a share of eighth on seven-under.
'It was pretty bad,' Koepka told reporters. 'I didn't hit very good, didn't putt very good. It's kind of continuation of last two days. I haven't got any momentum. I played poorly.
'I need to play better. If I can put a good round together, I should have myself in contention with nine holes to go. That's the plan.'
Overnight leader Emiliano Grillo managed only a level par 71 and fell to a tie for fifth on eight-under with Yuki Inamori (70) and another South Korean Japan Golf Tour regular in Ryu Hyun-woo (68).
The Argentine world No 48 was equally unimpressed with his round.
'Absolutely garbage to be honest,' he said. 'Didn't hit it good off the tee, didn't hit good second shot, putting was horrible. A lot of work to do tomorrow.'