Phachara Khongwatmai and Nino Bertasio posted rounds of 65 to sit at the top of a congested leaderboard after day two of the Maybank Championship.
Lee Westwood took the headlines in the morning with a brilliant 62 that got him to ten under and the clubhouse lead alongside Marc Warren and Yuta Ikeda.
It looked for a long time that the trio would share the lead heading into the weekend at Saujana Golf & Country Club but Khongwatmai had other ideas, making five consecutive birdies on the back nine to open up a one-shot advantage.
Bertasio then joined the lead from the last group of the day, making eight birdies and a bogey to get to 11 under.
Chris Paisley had held a one-shot lead when the first round was completed in the morning after Thursday's storm delay and he posted a 69 to join the group at ten under.
There were then 22 players within three shots of the lead, with the cut-line sitting just seven shots behind the leaders and leaving all to play for heading into round three.
Khongwatmai announced himself to the European Tour last season when, aged just 17, he finished second at the ISPS HANDA World Super 6 Perth.
He needed the Access List to keep his European Tour playing privileges last season but nearly 12 months on from that excellent week in West Australia, the Thai is once again showing his enormous potential.
"I’m very happy with my score," he said. "My plan is to shoot under par every day and play against the course.
"I don’t want to think ahead or compare my score to another player. It is only two rounds so the tournament is not over yet. I want to focus day by day and hole by hole."
I have been having fun on the golf course and playing well, so I’m looking forward to it - Nino Bertasio
The 18 year old turned in 34 with birdies on the fifth and sixth but came to life after the turn, with some brilliant iron play bringing him four birdies in a row from the 11th.
A 15-foot putt on the 15th made it five on the spin and Khongwatmai made a good up-and-down to save par on the 16th before missing two birdie chances on the 17th and last.
Bertasio finished 82nd in last season's Race to Dubai Rankings presented by Rolex and has now equalled his best run of eight consecutive made cuts as he goes in search of a maiden European Tour win.
"It was very easy to be honest," he said. "I’ve been playing the par fives well so a couple of birdies here and there on the par fours and par threes and here I am at 11 under.
"I have been having fun on the golf course and playing well, so I’m looking forward to it."
The Italian birdied the 12th and 13th and, after a bogey on the next, made further gains on the 15th, 17th, 18th, first, fifth and sixth.
Earlier, Englishman Westwood - a two-time winner in Malaysia, including the latest of his 23 European Tour wins in 2014 - made 11 birdies and a single bogey to catapult himself up the leaderboard on a day when 15 different players held a share of the lead at some point.
Scot Warren also had a single bogey on his card in a 66 while Japanese Ikeda was bogey-free in his 64.
England's Paisley fired a closing 66 to win the BMW SA Open Proudly hosted by the City of Ekurhuleni and he has gone sub-70 in all of his ten rounds since, carding a 69 on Friday thanks to a stunning tee-shot on the 16th and a lengthy closing putt.
Spaniard Jorge Campillo, South African Dylan Frittelli, Scot Stephen Gallacher, German Maximilian Kieffer, American David Lipsky and Japanese duo Daisuke Kataoka and Hideto Tanihara were then at nine under.
