Emiliano Grillo's commanding lead at the Mayakoba Classic has been slashed to a single shot after Tom Hoge, Viktor Hovland, Adam Long and Justin Thomas launched third-round charges in Playa del Carmen, Mexico.
Grillo, chasing a second PGA Tour win, began the day four clear of the field but the Argentine's three under 68 and 16 under total was barely enough to hold off Hoge, who collected birdies over five of his final six holes for a six under 65 to sit one back.
"Started in the lead, finished in the lead, that's kind of the idea," Grillo said. "Hopefully, one more of those.
"I just finished under par, finishing with the lead again that's kind of what I take from today, take into tomorrow."
Hovland made a stumbling start at the sun-kissed El Camaleon Golf Club with a bogey on his opening hole but that was his only mistake, the Norwegian hitting back with nine birdies for an eight-under 63 to lurk two back.
Long shot into contention with the help of seven birdies on his front nine in an eight under 63 to sit three off the pace while Thomas had the round of the day, a bogey-free nine under 62 to join Patrick Rodgers (65) one stroke further adrift.
"Try not to get wrapped up in where I'm at or what I'm doing," said world number three Thomas. "I'm trying to birdie every single hole.
"I just need to try to go out tomorrow and shoot another low one because you kind of can't put a ceiling on this place when you're playing it, you've just got to try and make as many as you can."
Northern Ireland's Graeme McDowell had missed the cut after Friday's second round after finishing on one over for the tournament.
