BANGKOK, March 29, 2013 (AFP) - The six-time Asian Tour winner is on a 12-under-par 132 total, but a host of big names are hot on his heels, including Thailand's Thongchai Jaidee and Asia's first Major champion Y.E. Yang of South Korea.
Thongchai, who needs a win in Chiangmai to qualify for the Masters Tournament, shot an impressive 65 to move to tied second place with American Jonathan Moore (68) and India's Digvijay Singh, who birdied his last three holes for a 67.
China's Hu Mu stayed in the title hunt with a solid 69 for tied fifth place, while Yang shot 68 to tie in 12th.
Prayad credited his fine form to his new irons and golf ball.
"I changed to a new golf ball and it seems to be giving me more distance," he said.
"Last time I hit my driver to about 280 yards but now I'm hitting it 20 yards longer. I'm getting more distance and that's good for my age," said the 47-year-old.
Four-time Major winner Ernie Els of South Africa struggled to a 71 for tied 41st place on 140.
"I was kind of facing an uphill battle... Missed a short one on three and three putted five (for bogeys)," said the reigning British Open champion.
Els, who said he was now too far back to challenge for the title, sent his wishes to former South African President Nelson Mandela, who was hospitalised late on Wednesday for a recurring lung infection.
"I just want to say that our thoughts are with our former president, President Mandela. He's going through a bit of a tough time now and as South Africans, we want to wish him all the best," said Els.
Scores after round 2 of the Chiangmai Golf Classic being played at the par-72 Alpine Golf Resort course:
132 - Prayad Marksaeng (THA) 65-67
134 - Jonathan Moore (USA) 66-68, Digvijay Singh (IND) 67-67, Thongchai Jaidee (THA) 69-65
135 - Hu Mu (CHN) 66-69, Pawin Ingkhapradit (THA) 67-68, Bryce Easton (RSA) 68-67, Matthew Stieger (AUS) 68-67
136 - Jason Knutzon (USA) 67-69, Mithun Perera (SRI) 70-66, Siddikur (BAN) 69-67