Graeme McDowell endured a day in the Honda Classic after a bogey-ridden third round.
The Antrim man sank three bogeys and two double bogeys along with just one birdie on the way to carding a six-over 76, and eight-over for the tournament.
Meanwhile, American Wyndham Clark posted a three-under-par 67 to take a one-shot lead into the final round at Palm Beach Gardens.
Clark has never won on the PGA Tour but the 25-year-old has shown good form recently, with top-20 finishes at the Puerto Rico Open and the Desert Classic.
Vijay Singh is one shot off the lead alongside South Korea's Kyoung-Hoon Lee and American Keith Mitchell, after firing five birdies in a best round of the day 65.
The 56-year-old Fijian is hoping to become the oldest winner on the PGA Tour and beat the record currently held by Sam Snead, who was 52 when he won the 1965 Greater Greensboro Open.
Rickie Fowler is two shots off the lead in fifth after a third-round 66, while three-time major champion Brooks Koepka is among a group of players another shot further back.