Graeme McDowell and partner Gary Woodland opened with a 13 under 59 in the scramble format to share second spot behind Matt Kuchar and Harris English in the Franklin Templeton Shootout in Florida.
Kuchar and English posted a 14-under 58 at the Tiburon Golf Club leaving Billy Horschel-Hunter Mahan and McDowell-Woodland to settle for second with 59s on day one.
"Having Kooch as a backup guy is pretty good," English said. "I know if I mess up or I miss a putt, I wouldn't want anybody else hitting a shot or putting behind me."
Since being paired in 2013, Kuchar and English have gone 79 under in their seven rounds - an average of a little better than 11 under per round.
The format on Friday is modified alternate shot.