Kiradech Aphibarnrat joined Martin Kaymer at the summit as the leaderboard tightened up on day three of the Abu Dhabi HSBC Championship.
Kaymer is seeking a fourth title at Abu Dhabi Golf Club but he dropped a single shot in his first four holes to drop to 11 under alongside Aphibarnrat who made an early birdie.
US Open champion Dustin Johnson has been struggling with jet-lag this week but the American picked up six shots in his first 15 holes to sit one off the lead alongside Byeong-hun An, Paul Dunne, Tommy Fleetwood and Pablo Larrazábal.
Johnson made an early move with birdies on the first, third and sixth and a chip-in eagle on the eighth before reeling off six straight pars.
Once the leading groups got under way, 2014 champion Larrazábal showed he meant business by holing a bunker shot on the first but fellow Spaniard Rafa Cabrera Bello endured a rough start as he looked to be struggling with a back injury.
The Ryder Cup star bogeyed the first and second to go from being nearest challenger to three behind Kaymer at nine under.
It was Aphibarnrat who then took his place as Kaymer's nearest rival, putting his tee-shot to ten feet on the par three fourth and making his birdie to get to 11 under.
An was also making his move and he turned in 32 thanks to birdies on the third, fourth, eighth and ninth, while Johnson broke his run of pars by putting his tee-shot close on the tough par three 15th.
Kaymer then made his first mistake of the day as he put his tee-shot on the fourth into the sand and failed to get up and down.
Englishman Fleetwood and Ireland's Dunne were level par for the day through four holes.
England's Callum Shinkwin set the clubhouse target from the second group out of the day, making birdies on the first, third, sixth, tenth, 13th, 16th and 18th for a 65 to get to nine under.
Dean Burmester, Sam Brazel, Bradley Dredge, Peter Hanson, Maximilian Kieffer and Marc Warren were also in that group with Cabrera Bello, with 12 players within two shots of the lead.
