Starting from the 10th tee, Shaaban turned in 37 but bounced back with a flawless back nine courtesy of six birdies for a two-shot lead over little known Steven Hiew at the RM150,000 event, which rewards the winner with a spot in the lucrative CIMB Classic in October.
Lim Eng Seng, Mohd Rizal Amin, an Asian Development Tour (ADT) regular, and Nicholas Fung shared third place following a 69 while Danny Chia and M. Sasidaran were a further shot back at the Mines Resort and Golf Club.
Shaaban shot five birdies in the closing six holes to give himself an opportunity of qualifying for a third consecutive appearance in the CIMB Classic, which is sanctioned by the Asian Tour and PGA TOUR.
"I'm familiar with the greens. There's pressure on all of us to win this event but I'm confident of winning. Every time I play here, it feels like I'm playing on my home course because I play here often," said Shaaban.
"There's a strong field this week but I'm only concentrating on my game and we will see where it takes me," added the Malaysian, whose best finish on the Asian Tour this year is a tied 13th result in Singapore.
Hiew, who is playing in his first professional event this year due to health issues, produced his best score at The Mines with four birdies and one bogey.
"I had good luck today [Monday] because I hit it close and holed all my putts. I'm very surprised with how I played as this is my best round on this course. To be honest, I'm not thinking about qualifying for the CIMB Classic yet. I just hope I can maintain my form," said the 43-year-old, who owns a company dealing with frozen food.
Fung finished as the highest ranked Malaysian in last week's Worldwide Holdings Selangor Masters and knows he needs to wield a hot putter in his quest of qualifying for the CIMB Classic, which will be headlined by 14-time Major champion Tiger Woods.
"I could have gone lower but missed a few short putts. It is always nice to be playing after a good tournament. I gained a lot of experience last week. I'm in good form but I didn't putt as well as I did last week," said Fung.
Leading first round scores
66 - Shaaban Hussin
68 - Steven Hiew
69 - Mohd Rizal Amin, Nicholas Fung, Lim Eng Seng
70 - Danny Chia, Wilson Choo, M. Sasidaran, R. Nachimuthu
71 - Sofian Kepli, S. Siva Chandhran, Kemarol Baharin, Mohd Sukree Othman, Mohamad Azman
72 - Md. Rashid Ismail, Jeremiah Kim, Chan Soo Keong
73 - P. Gunasagaran, Nicholas Pua