First round leader Ross McGowan, Swede Alex Noren and Australian Marcus Fraser were tied for third on nine under, while France’s Romain Wattel had made the day’s biggest move, five birdies in his first 12 holes taking him to eight under.
Garcia finally ignited his round with a 15 footer on the seventh and repeated that for eagle at the next.
With Noren losing his drive and taking seven there, the 2008 winner, who also eagled the hole in his second round, was suddenly four clear of McEvoy, McGowan and Fraser at 14 under.
Garcia's advantage went to five when McEvoy three-putted the ninth and both Fraser and McGowan bogeyed the 11th.
It came back to four, though, when Thai Thongchai Jaidee birdied the 11th and 13th.
Garcia swept six clear with a hat-trick of birdies in the middle of the back nine.
He was fortunate to run through a bunker with his second to the long 13th, but two-putted from the fringe, made a ten footer at the next and then holed a 20 foot putt from off the 15th green.