Bangkok: Thailand`s Sattaya Supupramai and George Gandranata of Indonesia took an unexpected lead at the Chiangmai Golf Classic on Thursday, striking a six-under-par 66 in the opening round.
The pair overshadowed major winner Jason Dufner of the United States, who finished with 69 and a share of 11th place in the $750,000 Asian Tour event.
Meanwhile 2011 Masters Tournament winner Charl Schwartzel of South Africa slipped to a 77.
Sattaya said he was "playing with a lot of confidence" after winning on the Asian Development Tour last week.
"We have a strong field here this week but I`m only focused on every shot and not the players who are here," said the 30-year-old in a statement released by organisers.
Gandranata, who tied him for the lead after closing with a pair of birdies, has never been ahead in an Asian Tour tournament before.
"There are still three more rounds to go. I have to focus on every shot and see how it goes," said Gandranata, who has won four titles on the local circuit this year.
Singapore`s Mardan Mamat took solo second at the Alpine Golf Resort, while title holder Scott Hend of Australia birdied the last hole to finish on 72.
The 2013 PGA Championship winner Dufner ended the round within striking distance of the leading duo.
"My front nine was a little slow to start but I played better on the back. It was pretty good all day. I`m glad to finish under-par," he said.