HONG KONG, 18 Oct, 2014 (AFP) - The 36-year-old has spent most of this year "sitting on the couch" after surgery for a hand injury but sits top of the leaderboard in the southern Chinese city ahead of compatriot Scott Hend.
Four-time major winner Ernie Els -- the overnight leader -- endured a difficult day stumbling to a one-over-par 71 to lie three shots behind Fraser going into Sunday.
Fraser, ranked 282 in the world, last played competitive golf in February when he was forced to retire from the Dubai Desert Classic during the second round because of excruciating tendonitis in his left hand.
Surgery to remove bone, three months worth of injections and rehabilitation followed, with Fraser only able to start practising again six weeks ago before getting back into competitive golf on Thursday.
"No one is more surprised than I am, that's for sure, after eight months of sitting on the couch," Fraser told reporters at the Hong Kong Golf Club.
"I wasn't really sure what to expect. To come in and play the way I did on the back nine today was pretty pleasing," he added.
Fraser -- who has two European Tour wins -- started with a bogey but bounced back with six birdies, including four on the inward half.
"I'd forgotten how much fun it is to play a golf tournament, especially being in the mix," he said, adding that his hand feels stiff.
"I had no idea coming into the week and I've got no idea going into tomorrow.
- Els struggles on greens -
"Hopefully I'll just go out and keep playing the way I'm playing and I feel pretty comfortable out there at the moment," he said.
Els felt considerably less comfortable during round three at the par 70, 6,699-yard course in Fanling, picking up a double-bogey and finishing with two bogeys in the last four holes.
The double came on the ninth when the big South African was forced to take a penalty drop after hitting his tee shot into a hedge.
It was an up-and-down day for Els who enjoyed an eagle at 13 and a birdie on the next hole before four missed putts derailed his round.
"I hit a lot of shots to the right today which cost me and I'm struggling with a right hip. There's a bit of pain there," said Els.
"I also missed a couple of putts but other than that I'm fine. It's disappointing but I'm still in with a chance tomorrow.
"I'll be looking for a 63," he added.
Els is one of five players on 8-under, including France's Raphael Jacquelin and Spaniard Javier Colomo who shot a round-of-the-day 64.
Australian Hend is on his own in second place at ten-under par while South African Jbe Kruger, Filipino Angelo Que and England's Mark Foster are on nine-under.
The Hong Kong Open is a co-sanctioned European/Asian Tour event.
Leading scores after the third round of the Hong Kong Open on Saturday (par 70):
199 - Marcus Fraser (AUS) 67-67-65
200 - Scott Hend (AUS) 67-66-67
201 - Mark Foster (ENG) 67-68-66, Jbe Kruger (RSA) 66-69-66, Angelo Que (PHI) 65-69-67
202 - Javier Colomo (ESP) 68-70-64, Jyoti Randhawa (IND) 64-70-68, Cameron Smith (AUS) 68-65-69, Ernie Els (RSA) 66-65-71, Raphael Jacquelin (FRA) 66-67-69
203 - Kevin Phelan (IRE) 69-67-67, Adam Groom (AUS) 67-68-68