Gallacher surges ahead in Dubai
The Scot shot a marvellous nine under par to head the leaderboard at the end of the third day with an overall score of 16 under.
Defending champion Gallacher looked to be heading for a disappointing round when he bogeyed the par-four eighth.
However, the world number 67 responded magnificently, picking up shots on nine of the next 10 holes, including an eagle at the 13th to boost hopes of only a third European Tour win of his career.
Gallacher will need to be wary of the challenge posed by world number six Rory McIlroy, who is well poised to charge for the title at 14 under, despite an inconsistent third round.
McIlroy made a poor start with a bogey on the first hole, but recovered with a birdie and an eagle on the next two.
The Northern Irishman then bogeyed the sixth, but was faultless for the remainder of the round and picked up shots at the 10th and 17th to keep himself in the fray,
American Brooks Koepka is tied with McIIroy in second, along with Thorbjorn Olesen after the Dane carded an excellent seven under par third round.
Englishmen Robert Rock and Steve Webster are also in contention at 11 under, along with Italy's Edoardo Molinari.
And, although he expressed satisfaction with his performance, Gallacher knows that victory is far from secured.
"I hit it stiff on nine and from then on just kept hitting it close, and if I hit it to 30 feet I holed it," Gallacher said.
"I was just trying to make as many birdies as I could and get a lead because I found the last time it's easier when you are leading than chasing.
"There's a lot of golf left to go but I will certainly be giving it my best shot."