Garcia, who was tied for the lead at the halfway stage with Englishman Justin Rose, took his three-day total to 18-under in the $1 million (£613,000) Asian Tour event at the Amata Spring Country Club.
World number three Swede Henrik Stenson matched Garcia's 65 and shared the second place alongside India's Anirban Lahiri who carded a 67.
Rose bogeyed his final hole for a two-under-par 70 to sit at fourth spot, five strokes behind the leader.
"It was great obviously to be able to go out there and shoot 65 again," Garcia told reporters after sinking eight birdies, including two on the final holes, against a lone bogey.
"I played nicely and felt pretty comfortable. I was able to hit some really nice shots and then was able to roll two or three really good putts in and it was nice to be able to finish birdie, birdie on this difficult finishing stretch."
The Ryder Cup hero was aware of the low-scoring conditions and a possible challenge from Stenson, who became the first man to win the U.S. Tour's lucrative FedExCup series and finish top of the European money list in 2013.
"Not only Henrik... there are probably five or six guys who can shoot a really good number. It's going to be exciting tomorrow," said Garcia, who had his girlfriend Katharina Boehm caddying for him.
"I want to try to be as aggressive as possible. I want to still try to make as many birdies as I can and if I manage to do that, then I'm going to put it quite difficult to the rest.
"I think if I start getting a little defensive, then I can give them a good opportunity of catching me."
A bogey-free third round has rejuvenated Stenson, who was preparing a final charge.
"That was a good day," Stenson, 37, said. "It was definitely the best I played this week. Made some good birdies and some really good saves to keep the momentum going. Those were crucial.
"Even though I'm tired and worn out, as soon as you see your name on the leaderboard, all of a sudden that tiredness goes away and you're looking forward to be there and hopefully have a chance to win.
"I know Sergio is desperate to get his hands on a trophy but I'll try to challenge him."
- Sports & Recreation
- Henrik Stenson
- Amata Spring Country Club