Kuala Lumpur - Thai teenager Phachara Khongwatmai posted a bogey-free round 65 to share a joint single-stroke lead with Italy's Nino Bertasio at the halfway stage of the Maybank Championship in Malaysia on Friday.
The duo hold a marginal advantage over Scotland's Marc Warren, Japan's Yuta Ikeda and English duo Lee Westwood and Chris Paisley, who are all tied on third.
Thai sensation Phachara, 18, said he learnt a lot from the match-play style tournament.
"My partner Hideto Tanihara taught me a lot and he calmed me down because I was very nervous," Phachara, who shot seven birdies, told reporters.
"It has been a long time since I've been bogey-free. I putted very well because I didn't hit the ball close to the hole."
Earlier, Westwood finished with a 62 after an astonishing 11 birdies at the Saujana Golf and Country Club, where he won the Malaysian Open in 1997.
"It's nice to be in contention and to know this golf course well," Westwood, 44, said.
A competitive field saw a host of golfers remain only two shots off Phachara and Bertasio in tied-seventh, including last year's runner-up David Lipsky of the United States.
Top-ranked Henrik Stenson of Sweden also made the cut after an improved performance for a 67 to lurk six shots from the joint leaders.
Perhaps the biggest name to miss the cut was China's Li Haotong, who finished in an abysmal tied-125th.
There were high hopes that Li would stamp his mark on this tournament after his eye-catching victory at the Dubai Desert Classic last week, where he upstaged four-time Major winner Rory McIlroy.
Leading scores after the second round of the Maybank Championship Malaysia (Par 72):
133- Phachara Khongwatmai (THA) 68-65, Nino Bertasio (ITA) 68-65
134 - Lee Westwood (ENG) 72-62, Yuta Ikeda (JPN) 70-64, Marc Warren (SCO) 68-66, Chris Paisley (ENG) 65-69
135- Stephen Gallacher (SCO) 70-65, Daisuke Kataoka (JPN) 68-67, Hideto Tanihara (JPN) 71-64, Dylan Frittelli (RSA) 69-66, David Lipsky (USA) 67-68, Maximilian Kieffer (GER) 69-66, Jorge Kampillo (ESP) 69-66
136- Andrew Dodt (AUS) 71-65, David Horsey (ENG) 66-70, Ryan Fox (NZL) 68-68, Danthai Boonma (THA) 70-66, Robert Karlsson (SWE) 68-68, Thomas Detry (BEL) 68-68, Thomas Bjorn (DEN) 68-68, Thongchai Jaidee (THA) 69-67, Prayad Marksaeng (THA) 71-65, Soren Kjeldsen (DEN) 69-67, Lee Soo-Min (KOR) 67-69