O’Flaherty, who finished on a total of 212 after a closing 71, won by two shots over Mallow’s James Sugrue, with Castletroy’s Andrew McCormack third, both on two-under par.
“The key today was don’t make any mistakes, stay in the hunt and see what happens next. Thirteen was a turning point for me. I chipped in for birdie and it got me back on track again. I played pretty solid, I didn’t make any big mistakes.
“Making birdie on the 15th was a big moment and gave me that gap of two shots that got me ahead,” O’Flahery said.
Meanwhile, Bernd Wiesberger was crowned the Shenzhen International champion after beating Tommy Fleetwood in a dramatic play-off at Genzon Golf Club.
The Austrian was in control heading into the final day in China, holding a three-shot lead, but could not have envisaged the kind of performance Fleetwood was to produce.
The Englishman, eight shots behind at the start of his final round, carded an excellent 63 to level with Wiesberger, who could only par the 18th, on 16 under to ensure another trip to the last hole in the rain.
But Wiesberger held his nerve to secure a fourth European Tour victory in his 200th event, putting for birdie despite ending up in the bank after opting to take the risky line over the water off the tee.
The play-off victory was the first for in-form Wiesberger, who has not missed a cut since the US PGA Championship, in four attempts.
He said: “I knew it was going to be hard, I knew I would have to shoot well under par to make it outright because the guys behind were all really playing well.
“I just wanted to get off to a good start and show them that I’m up for it and I did, scrapped around a little bit, had a couple of near misses with good looks at it early on. It could have got to me but I stayed calm, played on decently.
I’ve had a stretch of really good events the last couple of months and it’s really nice.”
Frenchman Gregory Bourdy and England’s Ross Fisher finished one shot behind the co-leaders on 15 under, one ahead of Fabrizio Zanotti, David Lipsky and Dylan Frittelli.
Two-time former Masters champion Bubba Watson fired a final round two-over par 74 to finish eight under.