France's Dubuisson carded a 67 to tie with overnight leader Van Zyl of South Africa on 16 under par.
McIlroy carded a third straight five under-par 67 to move to 15 under par with Thailand's Kiradech Aphibarnrat.
The world number three's round included an eagle on the 12th as he bids to win his first title since May.
"The 67s I've shot this week have all been a little different and I feel like I've played within myself for all of them, " said four-time major winner McIlroy of Northern Ireland. "I feel there's a low round out there for me and hopefully it's tomorrow."
McIlroy was level par for the day after 10 holes, dropping his first shots of the week by three-putting the third and 10th, the latter mistake prompting the 26-year-old to throw his putter at his bag.
But he hit back with a birdie on the par-five 11th and a towering four iron from 229 yards on the 13th set up an eagle from just four feet.
The former world number one ruptured a ligament in his left ankle during a game of football with friends in July, ruling him out of several tournaments.
But he returned in time to unsuccessfully defend his US PGA title at Whistling Straits in August and played in three of the FedEx Cup play-off events before starting the new PGA Tour season with a tie for 26th in the Frys.com Open in California.
He is targeting a third Race to Dubai title in four years and leads England's Danny Willett by 271, 214 points with three events remaining after the Turkish Open.
English pair Chris Wood (-13) and Richard Bland (-12) who were tied for second overnight are fifth and seventh respectively.
Rory McIlroy moved to within a shot of joint leaders Victor Dubuisson and Jaco van Zyl after the third round of the Turkish Airlines Open.