Australian Unho Park has relinquished his first-round lead at the Singha Thailand PGA Championship and is tied with three other golfers in fourth on seven under. Park signed off for a two-under par second round of 70 and now finds himself six strokes adrift of leader Juvic Pagunsan. Park&aposs fellow first-round leader and compatriot Terry Pilkadaris is on four under overall after he recorded a horror one-over-par round on day two. Pagunsan carded a stunning 63 to move one shot clear of home favourite Prayad Marksaeng. Pagunsan, of the Philippines, began the day on four under, one shot behind four players – including Prayad – who were tied for the overnight lead. The 30-year-old struck 10 birdies, including a run of seven on his incoming nine, to move to 13-under-par 131, while Prayad signed for a 65 and South Korea`s Mo Joong Kyung was alone in third place after a 64 took him to 11 under at Santiburi Country Club. Pagunsan, chasing his second Asian Tour victory, started on the 10th hole and made birdies on the 12th, 13th and 18th with a solitary dropped shot on the 14th. That birdie on 18 sparked a remarkable run, with consecutive birdies following from the first to the sixth holes. A further birdie followed on the eighth as Pagunsan carded 29 on the front nine. “That was a very special round,” said Pagunsan, who won the 2007 Pertamina Indonesia President Invitational. “I hit it good and putted very well. It&aposs the first time I&aposve shot seven straight birdies in my career and I was just in a zone and focusing hard on each shot.” Pagunsan admits he would rather not be leading the field, having failed to handle the pressure before. “I can&apost say that I&aposm comfortable being in the lead as there are just so many good players in Asia these days,” he added. “I threw away a four-shot lead at the Volvo Masters and I can only learn from my mistakes then. “It&aposs hard to win but I will certainly try.” Thai number one Prayad, seeking a seventh Asian Tour title, is likely to launch a challenge over the weekend. Prayad has won the Mitsubishi Diamond Cup and the Mizuno Open in Japan within the last month and carded six birdies and an eagle, with one bogey, while Mo was bogey-free in his eight-under round.