Westwood added a 66 to his opening 65 for a 13-under-par halfway total of 131, four shots ahead of Ryder Cup team-mate Nicolas Colsaerts and Antonio Lascuna of the Philippines.
Sheffield’s Danny Willett is a further shot adrift after carding a 66. Westwood’s super performance was somewhat overshadowed by a bizarre incident involving Larrazabal, who shot a remarkable 68 despite having to dive into a lake after being attacked by hornets.
The incident happened on the fifth hole at Kuala Lumpur Golf and Country Club – Larrazabal’s 14th hole of the day – and after drying off and receiving treatment, the 30-year-old went on to birdie the par five and make another on the seventh.
“I hit my tee shot just right of the bunker and chipped it out quite well,” said Larrazabal. “So I’m walking along and suddenly I felt something on my nose. I swatted it away and suddenly... they were not bees, they were three times the size of bees.
“They were huge and like 30 or 40 of them started to attack me big time. I didn’t know what to do. My caddie told me to run, so I start running like a crazy guy, but the hornets were still there, so the other players told me to jump in the lake.
“So I ran to the lake, threw my scorecard down, took off my shoes and jumped into the lake. It was the scariest moment of my career, for sure. I’ve never been so scared.
“I had to throw my shirt and hat away, and the towel I’d been swatting them with. The referees and a doctor took me aside and gave me a couple of injections and told me to relax. After the injections I felt a lot better and could continue. Without the help of the referees I couldn’t have finished the round, because I was in no state to play golf.
“It will be very, very scary to play that hole. I’m not sure what I’m going to do, but, hopefully, I will play it as quickly as I can.”
Twelve of the Englishman’s 40 career wins coming on the continent.
Sheffield’s Matt Fitzpatrick, the US Amateur champion, was on course last night to make his first cut on the PGA Tour after carding a second successive level-par round of 71 at the RBC Heritage at Hilton Head.