The South African, who lost out on the green jacket to American Bubba Watson on Sunday, was in a tie for third after the first round of the European and Asian Tour co-sanctioned event, two behind leader Charl Schwartzel (64).
The duo looked refreshed ahead of their early tee time at the Kuala Lumpur Golf and Country Club and the South African pair clearly enjoyed each other's company as they laughed and joked around in the cooler, morning temperatures.
"I feel like I'm swinging it well and I think a lot of times I'm used to a lot of travel so you adapt quickly," Oosthuizen, the 2010 Open champion, said.
"We knew there would be one tough round and it is normally the first one and it was lucky for us that it was earlier in the morning so we can have a nice rest (this afternoon)."
Oosthuizen, also grouped with Thailand's Thongchai Jaidee (73), received the loudest cheer from the small galleries that woke early to see how he would react to the heartache of missing out in the play-off to Watson at the year's first Major.
After pulling his drive slightly left on the par-five 10th, his first, he munched down an apple before firing a fairway wood to the edge of the uphill green and then chipped up and down for a birdie four.
A good tee-shot at the 226-yard par-three 11th set up a nine-foot birdie putt, which the South African rolled in to give him a dream start and a second two came at the 15th when he rifled his 199-yard approach next to the pin.
The highlight of his day, though, was an eagle three on his 12th.
"I hit a three iron in there and I made a nice long putt," the gap-toothed South African said. "I thought I would struggle a bit more on the greens, speed wise, but I felt comfortable and I made quite a few putts."
The only negatives for the 29-year-old world number 19 was two dropped shots on his back nine, the par four 10th and 15th but they were offset by further birdies at the 13th, 14th and 16th.
"I felt good, swing was still fine played well, made two stupid bogeys but yeah it was still good. I had a good night’s rest and I'll try for the next 24 hours to hopefully have a lot of rest," the four-time European tour event winner said.
Playing partner Schwartzel, who finished 11th here last year after he had gone one better than his compatriot and won the Masters title, produced nine birdies in his round as he took an early clubhouse lead at the $2.5 million event.
"Very, very good," was Schwartzel's review, as he looks to win his first title since his Augusta triumph.
"I have worked hard at my game for the last couple of weeks, last couple of months and haven't had anything happen for me. But it has been feeling good for a long time and today I seemed to put it together, eight-under is a good score for me."
The pair both credited the early tee-time as having a positive effect on their game, allowing them a long time to rest and fully overcome the jet-lag before their second round starts in the Friday afternoon heat.
"We both got off to really good starts in the beginning and it helps if you see guys making birdies as you know they are out there and Louis is playing so good right now so it is nice to watch," Schwartzel said.
Schwartzel is one shot clear of India's Jeev Milkha Singh with his compatriot Jyoti Randhawa and American Jason Knutzon joining Schwartzel on six-under.
World number seven Martin Kaymer of Germany had five birdies, two double bogeys, one bogey and an eagle in an eventful 70, a score matched by defending champion Matteo Manassero of Italy.