Greg Owen, Alejandro Cañizares and Richard S Johnson will have work to in the final round of the Mayakoba Classic after Daniel Summerhays took a two stroke lead by shooting 67 at Mexico's El Camaleon resort.
The 28 year old hit four birdies as he finished the day 12 under par and stretched out what had been a tightly packed leaderboard.
Summerhays had started the day level at the summit with fellow American Will Claxton and England's Owen, who both fell off the pace today after rounds of 71 and 73 respectively.
Instead, it was left to Chris Stroud to provide Summerhays' main challenge as he moved to ten under with a three under 68, following rounds of 69 and 66 on the first two days.
Claxton would have been level with Stroud but bogeyed the last two holes to slip back to his overnight eight under, level with Michael Allen after the latter made a 66 which included an eagle at the fifth.
Marc Turnesa and Robert Allenby follow a further shot back, while Owen's six bogeys cancelled out his four birdies to drop him into a six-strong group at six under, one ahead of Cañizares and Johnson.