He led the morning field, one stroke clear of Desvonde Botes, who carded a superlative seven-under-par 65 on the par 72 East course.
McGrane who played on the West course said: “I am delighted to be in a good position after round one.”
“For the last three or four years Irish golf has been quite incredible, and I think we feed off each other. For a small nation it sure is great to be there or thereabouts,” he added.
McGrane carded a solid seven birdies during the day, but the 40-year-old really vaulted into the lead when he chipped in for eagle at the 15th, moving two strokes clear of the competition.
“I stacked up a few birdies during the round, but that eagle really turned my round,” he said.
The morning field was treated to great conditions and the Irishman, who started playing golf in 1984, was up to the task and added: “I played beautifully from start to finish, and this course does give up opportunities. The greens and weather were perfect, so if you’re on your game there are birdie chances. Needless to say you have to make the chances and today I holed a few nice putts.”
He got his round going with a birdie at the second, but really found his groove three holes later, starting a run of three consecutive birdies at the fifth. He topped off the front stretch with a final birdie at the ninth turning at five-under.
He was in no way slowed after the turn and made birdies at the 11th and 12th for his first move to the front, and after two pars chipped in from four metres off the green to secure his position at the top of the leaderboard.
McGrane would lose his momentum with bogey on the 18th, the lone blemish on an otherwise flawless round.
“I hit plenty of fairways and holed a few nice putts for birdie, it was just the bogey at the last which was disappointing. Apart from that it was a perfect round of golf.
“There is no run on the fairways so the course plays very long and I had to use every club in the bag to get around the course. It’s about making the best of the situation,” said the 2008 Volvo China Open champion.
In sole possession of second was Botes, who followed a birdie at 17 with an eagle at 18 to tear up the back stretch of the East course in just 30 blows.
The Pecanwood Golf Estate professional had a calm front nine and made birdies at the first and ninth to turn at two-under, but his dominance of the second took him to his seven-under score.
“I played very nicely: bogey-free and sank some good putts. This is my best score around the East course and this is a good start to my year. I’m excited about the game and looking forward to the coming rounds,” he said.