COOLUM, Australia, Dec 14, 2012 (AFP) - Zhang fired back-to-back 67s to finish the second day at 10-under the card and lead the OneAsia co-sanctioned US$1.25 million tournament with Australian overnight leader Popovic, who shot a two-under-par 70.
In windy conditions, Zhang, 25, fired eight birdies and three bogeys, including a run of four consecutive birdies on the back nine.
He got to 11-under late in the round only to bogey the difficult 18th after hitting his approach shot too long and then just missing a putt to salvage par.
Zhang, from Shanxi in the north of China, otherwise putted superbly during his second round.
"I have been surprised by my putting," he admitted. "I needed just 22 putts, which is my best-ever round. I really like the greens here.
"But in the past two days I have also only been using a hybrid off the tee. I have only used a driver three times this week, so I have been very solid off the tee.
"With my approach shots, I am just trying to visualise them, to think about the shot and hit it. So far it is working."
Zhang missed the cut at last week's Australian Open at The Lakes in Sydney but said he didn't feel nervous heading into the weekend rounds.
"I'm not nervous at all, just enjoying myself and enjoying the game," he said.
Zhang, ranked No.793 in the world, left school at 15 with the ambition to become a security guard to help support his farmer parents.
His first posting was to a golf course where he was instantly hooked by the game, picking up a club for the first time when he was 17.
Popovic, who won the Australian PGA tour qualifying tournament last December, was delighted to still be leading after two rounds.
"I'm stoked, I can't get the smile off of my face actually since I finished the round," he said.
"It's an unbelievable experience, I can't even explain it, I'm lost for words explaining it.
"I got to bed pretty early last night but then I was just tossing and turning a bit in bed, as expected.
"It's such a big tournament, you watch this on TV as you are growing up and the cliche thing of you look up to these guys all the time."
Zhang and Popovic will be pursued by a group of bigger names in Saturday's third round, with Australia's former US Open winner Geoff Ogilvy two shots behind on eight-under following a three-under 69 on Friday.
"I feel like I am in a good place," said Ogilvy, who's been working on some swing adjustments.
"I like how I am playing and I am obviously quite comfortable on this golf course.
"I will be in one of the last few groups tomorrow and if I can have a good score and stay up there, I can give it a good crack."
Australians Mathew Goggin, Steven Bowditch and Brad Kennedy were next at 7-under in a tie for fifth.
Australian Open champion Peter Senior is on six-under along with Rod Pampling, while Northern Ireland's Darren Clarke is a shot further back on five-under.
Singapore's Choo Tze-Huang had a disappointing three-over 75 to slip down the leaderboard, however South African Rory Sabbatini made up for his poor first day by shooting a four-under 68 on Friday to finish even with the card.
Scores after the second round of the OneAsia co-sanctioned US$1.25 million Australian PGA at the par-72 Palmer Coolum Resort course on Friday (Australia unless stated):
134 - Daniel Popovic 64-70, Zhang Xin Jun (CHN) 67-67
136 - Geoff Ogilvy 67-69, Matthew Griffin 69-67
137 - Mathew Goggin 71-66, Steven Bowditch 70-67, Brad Kennedy 69-68
138 - Rod Pampling 71-67, Peter Senior 68-70
139 - Stephen Leaney 69-70, Steve Conran 69-70, Matthew Millar 73-66, Richard Green 71-68, Darren Clarke (NIR) 70-69, Leigh McKechnie 70-69, Jason Kang (USA) 70-69, Kurt Barnes 74-65, Scott Strange 66-73, Marc Leishman 69-70, Jamie Arnold 71-68
140 - Cameron Percy 70-70, Brendan Jones 73-67, Robert Allenby 73-67, Peter Fowler 70-70, Bronson La'Cassie 69-71, Stephen Dartnall 68-72, Heath Reed 72-68
141 - Adam Crawford 70-71, Anthony Brown 73-68, Josh Geary (NZL) 69-72, Greg Chalmers 72-69, Ryan Haller 68-73, Peter O'Malley 73-68
Selected scores
142 - Choo Tze-Huang (SIN) 67-75
143 - Choi Joon-Woo (KOR) 74-69
144 - Park Hyo-Won (KOR) 71-73, Park Ju-Hyuk (KOR) 77-67, Yi Cao (CHN) 73-71, Rory Sabbatini (RSA) 76-68, Kim Do-Hoon (KOR) 73-71
145 - Pravee Visalkt (THA) 74-71, Li Xinyang (CHN) 72-73
Missed cut
146 - Rory Hie (INA) 71-75, Garrett Sapp (USA) 73-73
147 - Huang Wen-Yi (CHN) 74-73
149 - He Ze-Yu (CHN) 78-71
150 - Masahiro Kawamura (JPN) 78-72, Simon Yates (SCO) 78-72, Chen Jian (CHN)
151 - Supravee Phatam (THA) 82-69
152 - Thomas Petersson (SWE) 78-74, Park Min-Jun (KOR) 78-74 Park Sang Hyun (KOR) 79-73
154 - Masaya Tomida (JPN) 74-80
155 - Choi Seong-Jin (KOR) 79-76, Park Sung-Hyuk (KOR) 78-77
157 - Jin Daxing (CHN) 75-82, Da Quan (CHN) 80-77
158 - Tanutchan Puaktes (THA) 79-79, Son Joon-Eob (KOR) 79-79
159 - Will Yanigasawa (USA) 81-78
160 - Wisut Artjanawat (THA) 77-83