Leader Ernie Els faces a tricky four-hole finish to the weather-hit Arnold Palmer Invitational when play resumes on Monday after he dropped three strokes just before a storm hit Bay Hill on Sunday.
"I'll be thinking about it all night. It won't be a very peaceful night I don't think but I am going to come out and get it done somehow," Els told reporters.
The South African has a two-shot lead over Kevin Na and was on the 15th hole when the storms moved in and officials called the players off the course.
Play was abandoned for the day around three hours later at 1730 local time and the tournament was scheduled to resume at 1000 on Monday.
Els, looking for his second straight win on the PGA Tour, was perfectly poised for a comfortable victory after moving five shots clear after a birdie at the 12th but on the next hole he went from fairway bunker to water and doubled bogeyed the par-four 13th.
"I was maybe too aggressive on my drive. I wanted to get it close to the green and I got the bunker, I had a good lie but the bunkers are a little softer than we are used to and I caught a little too much sand," said Els.
He found sand again on the par-three 14th and had to two- putt for another bogey after Na closed in with birdies on the 11th and 12th.
"Not a very nice way to go into a bit of a break. But I've got a two-shot lead. I started the day with a one-shot lead and I have two now.
"Obviously, I am not totally at ease with myself right now, I'm a little angry or disappointed but there is still work to be done and I've got to get it done," he added.
Organizers had brought tee times forward and sent out the players in groups of three rather than pairs in a bid to finish the tournament before the storm arrived -- but the thunder and lightning came an hour earlier than hoped.
Americans Chris Couch and Ben Curtis, who were in the final group with Els, had been on the South African's tail at the start but Couch bogeyed the 11th and 13th and Curtis had bogeys at eight and nine.
The pair were joined on eight under by Els's compatriot Retief Goosen while Italian Edoardo Molinari and American Kevin Streelman were a further shot back.
World number three Phil Mickelson had another disappointing day after he triple-bogeyed the third hole, taking two penalties for balls hit into the water.
The left-hander was five over for the round to finish two over for the tournament.