Bickerton had a 66 to match McGowan at 14-under 202 on The Vines Resort's composite course. New Zealand amateur Danny Lee, the U.S. Amateur champion, shot a 69 to join France's Raphael Jacquelin (66), Chile's Felipe Aguilar (68) and Australia's Terry Pilkadaris (68) at 12 under.
American Anthony Kim, two strokes out of the lead after the second round, had a 9 on the par-5 third and finished with a 75 to fall from a tie for sixth to a tie for 46th at 5 under. Second-round co-leader Anthony Kang, the American who won the Malaysian Open last week, also was 5 under after a 77.
Ireland's Damien McGrane, tied with Kang after the second round, shot a 72 on Saturday to drop into a tie for 12th at 10 under in the event sanctioned by the Australasian, European, Asian tours.
The 26-year-old McGowan is looking for his first European Tour win.
"It's where you want to be," McGowan said. "A good round tomorrow, and we'll see how it goes.
"I just hit the ball nicely and hit a lot of fairways. Around here if you can do that, the second shots, third shots, aren't too tough."
Lee had a chance to move closer to the lead, but bogeyed the par-3 16th.
"Not much happened today, and I wasn't driving the ball very well," Lee said. "That resulted in a lot of ups-and-downs. But I'm only two behind. I still think I can win this tournament."