The 78-man event features a prize purse of $9.25m (£7million) and a first prize of $1.6m (£1.2m), with US PGA champion and world No 4 Thomas the highest ranked player in the field on Jeju Island.
Thomas, a victor of four events and the FedEx Cup in 2017, could only manage a midfield finish last week in Malaysia but today it was a very much different story as, after a bogey at his starting hole (the 10th), it was all one way traffic, eagles at his 3rd from 20 feet and 9th holes, after a huge drive from 3 feet, racing him to the turn in 29.
The PGA Championship victor picked up further shots at the 16th and 17th before grabbing his second eagle in eight holes at the 18th. Leishman was treading water at even par after making three birdies and three bogeys on the front nine, but exploded on the back with four birdies and an eagle for 30.
While he struggled with his wedge play on occasion on Thursday, Thomas was happy with his driving but said he was not focusing too much on technique. “It started off with a really, really bad bogey”.
Thomas has won the CIMB Classic in Malaysia twice – in 2015 and 2016 – and says he is comfortable playing overseas.
“It’s still golf”, Thomas said.
“You just have to take advantage of the time away from the course and I have a a guy from my physio team over here with me this week to help in that regard”.
Adam Scott had a 72 containing four birdies and four bogeys.