Naples - Aussie Jason Day and US partner Cameron Tringale stayed hot on Friday, teaming for an eight-under par 64 that pushed their lead to three strokes in the Franklin Templeton Shootout.
Day and Tringale finished 36 holes of the 54-hole tournament for 12 teams of two at 25-under-par 119.
"We stuck to the game plan all day and I was able to get some nice tee shots out there and let Jason have at it," Tringale said. "We had a lot of short approach shots in again today and Jason putted great when I hit it close. He was banging them in. It was really a team effort out there."
The teams played a modified alternate shot format on Friday after playing a scramble on Thursday.
Saturday's final round will be a better-ball format.
Graeme McDowell and Gary Woodland combined for a nine-under 63, the low round of the day Friday. They moved into second place at 22-under-par 122.
The defending champions, Harris English and Matt Kuchar, posted a six-under 66 and were alone in third at 21-under.
Day and Tringale's round included Day's 15-foot eagle effort at the sixth, as well as three straight birdies at eight, nine and 10.
"We played great out there today," said Day, who at eighth in the world is the highest ranked player in the field. "We left a few out there, but any great round you're going to leave a few out there. I'm excited for tomorrow."
Northern Ireland's McDowell, the 2010 US Open champion, aided the cause of himself and Woodland when he holed a short wedge shot at 13th for eagle.
"That little 48-yarder my partner left me (on 13) really got the round going," he said.