Brier holed seven birdies on his way to the top of the leaderboard
Second round leader Raphael Jacquelin fell off the pace at the Volvo China Open in Shanghai after a costly four-over round of 75.
(GB & Ire unless stated)
-6 M Brier (Aut)
-5 S Hend (Aus)
-4 A McLardy (SA)
-3 G McDowell, R Jacquelin (Fr)
He ended the day alongside Graeme McDowell and Richard Sterne on three under, three shots behind new leader Markus Brier.
McDowell said: "I think I'm in a great position only three shots back going into the last round.
"I hope it stays tough, like it is today. I'll be there or thereabouts."
Austrian Brier's four-under round of 67 included seven birdies and three bogeys as he went to six under overall.
Scott Hend is on five under, with Andrew McLardy a further shot behind.