BANGKOK, December 13, 2013 (AFP) - Garcia fired a sizzling seven-under par 65 which included a hole-in-one at the eighth, while Rose shot an accomplished 68 as the duo reached 11-under for the tournament.
Rose and Garcia are two strokes ahead of overnight leader Alex Cejka of Germany, France's Alexander Levy and India's Anirban Lahiri, who shot the day's lowest score, a magnificent eight-under 64. A further stroke behind was America's Rickie Fowler.
Pre-tournament favourite Henrik Stenson improved on his opening round with a 67 to move into joint seventh place with a cluster of players including Thailand's leading contender Kiradech Aphibarnrat and India's Sujjan Singh.
"It was a wonderful day," said a happy Garcia who in addition to his hole-in- one, sunk five birdies. "The hole-in-one was an extra bonus. It is always an exciting feeling," said Garcia. It was his third ace in tournament play.
Garcia, who has his girlfriend on the bag, said he felt comfortable with his form. "I've been playing well both days," he said. "But there are still two days to go."
Rose said he was pleased with his score despite a rather shaky beginning. "It was a funny round," he said. "I got off to a slow start," which included a bogey at the third.
He added: "I had more trouble reading the greens today and was fortunate to make some big putts to save par."
However after a birdie at the ninth his game really stepped up.
"That birdie really got me going," Rose said.
And things soon got even better when he was rewarded with an eagle at the 11th.
"My approach was the best iron shot I have hit in months," he said. "I'm looking forward to playing with Sergio in the third round."
Overnight leader Cejka said he had played quite well but a double bogey at the 18th spoilt his day.
"That double was a real pity, otherwise it would have been a decent round," he said.
Lahiri found himself in possession of a hot putter, sinking six birdies, and an eagle at the par-five 11th hole.
"I've had a great day," he said. "I felt like I could sink everything."
The Indian star said his form had been good for some time.
"I've been knocking at the door in recent months, but just haven't quite finished it off."
Fowler celebrated his 25th birthday in the best possible way with a 66, featuring a string of birdies on the back nine.
"I finally got things going and hit some better putts," he said. "It was nice to finish off strong."
Defending champion Charl Schwartzel was well down the field in joint 19th place after a disappointing 73.
Scores after the second round of the $1 million Thailand Golf Championship on Thursday at the Amata Spring Country Club. (par 72)
133 - 68-65 Sergio Garcia (SPA), 65-68 Justin Rose (ENG)
135 - 64-71 Alex Cejka (GER), 71-64 Anirban Lahiri (IND) , 70-65 Alexander Levy (FRA)
136 - 70-66 Rickie Fowler (USA)
137 - 70-67 Henrik Stenson (SWE), 69-68 Kiradech Aphibarnrat (THA), 68-69 Sujjan Singh (IND), 72-65 Andrew Dodt (AUS)
139 - 65-74 Arnond Vongvanij (THA), 69,70 Masahiro Kawamura (JAP), 66-73 Gaganjeet Bhullar (IND), 71-68 Panuphol Pittayarat (THA)
140 - 71-69 Jaakko Makitalo (FIN), 70-70 Bubba Watson (USA), 73-67 Scott Barr (AUS)
141 - 72-69 Yuki Kono (JAP), 71-70 Jason Knutson (USA), 72-69 Chapchai Nirat (THA), 67-74 Daniel Chopra (SWE), 68-73 Mardan Mamat (SIN), 68-73 Charl Schwartzel (SAF), 71-70 Wade Ormsby (AUS), 70-71 Elias Bertheussen (NOR) , 74-67 Rikard Karlberg (SWE)
Selected Scores
143 - 73-70 John Daly (USA)