Sydney golfers James Grierson and Jordan Zunic share the lead after the opening round of the $50,000 Queanbeyan Regional Open.

Sydney duo James Grierson and Jordan Zunic share the lead after posting four-under-par 66s in the opening round of the $50,000 Queanbeyan Regional Open at Queanbeyan Golf Club.

Hometown hero Matt Millar and in-form Sydneysider Andrew Evans are both one shot adrift.

Hot on their heels are defending champion Deyen Lawson, Brady Watt, Nathan Barbieri, Alexander Simpson and Victorian amateur Andre Lautee, all just two shots off the lead at two under.

Grierson, 29, came from the "unseeded" side of the morning draw, but started in style with birdies on the ninth, 10th and 13th.

When the Forbes product turned and birdied the second and third holes, he threatened to blow the field away but fell back to four under with a bogey on the testing par-three sixth.

Zunic, who's as enthusiastic as he's been for years, made an adventurous eagle on the third when he tugged his drive far enough left that it bordered the fourth and seventh fairways.

Zunic made a bogey on the par-4 seventh hole, but took advantage of his length with two more back-nine birdies on the par-5s.

"I'm just learning to take advantage of things when they present themselves, so that was a good thing, too," Zunic said.

Fresh from a brilliant victory at the recent Japanese Tour Q-school, Evans went out hot and looked particularly ominous until a three-putt bogey on the ninth stalled him and sent him back to three under.

From there, Evans was all aboard the par train and finished at the same score.

The $50,000 Queanbeyan Open is the third event of the six tournament NSW Regional Open Series.

The Series is played at venues across NSW including Murray Downs, Dubbo, Queanbeyan, Moruya, Coffs Harbour and Tweed Heads.

The top three placegetters, not otherwise exempt, earn places in the 2022 Golf Challenge NSW Open to be played at Concord Golf Club in from March 17-20.