Harold Varner and Ryan Palmer equalled the lowest round at the QBE Shootout with a 17-under 55 on Friday.
The American duo birdied 15 of the 18 holes and eagled the 17th, with their only pars coming at the fifth and 16th.
Varner drained a 20-footer on the last to tie a record held by four other teams at the stroke play event.
That first-round score gave them a two-shot lead over Jason Kokrak and J.T. Poston, with the duo of Ian Poulter and Graeme McDowell in a tie for eighth after their 11-under 61.
"We're just having fun," Varner told the PGA Tour's website.
"We enjoy each other's company, even if it's not on the course, and it just meshed really well today.
"It's not like some person did this or that, it was just a lot of fun. I enjoy that team aspect, we were pretty pumped for this."
Had they shot 18 under par they would have broken the competition's single-round record, and Palmer joked those two pars cost them.
"I was really wanting 18, I thought we could get there," he added.
"You had the mental lapse, you make two pars like that..."