Despite a nervous start to the match when she lost her serve in the opening game, the reigning US Open champion quickly found her form to overcome Garbin in just 53 minutes.
Garbin had no answer to the 26-year-old Clijsters once the Belgian found her range, with an array of powerful and accurate groundstrokes proving lethal.
Clijsters' forehand was particularly damaging, pinning Garbin back in the corners and forcing a host of errors from her opponent.
The strength of Clijsters' groundstrokes put Garbin's serve under immense pressure and the Italian was unable to cope, making just 51 percent of her first serves.
Clijsters took full advantage and broke twice in the first set and twice more in the second as she booked her place in the second round.
The match was the former world number one's first on her full return to the WTA tour after retiring in May 2007.
She made a partial comeback last year, playing just four tournaments and culminating in her sensational US Open victory in New York.
"It was a nice feeling to be out there again," Clijsters said.
"I felt like my groundstrokes were going really good, I felt like I was standing up on the baseline and really changing the direction of the rallies."
The win delighted the large crowd packed into the Pat Rafter Arena, who gave Clijsters a rousing reception when she stepped onto the centre court.
It also kept alive the possibility of a dream final against fierce rival and fellow countrywoman Justine Henin, who will play second seeded Russian Nadia Petrova in the first round on Monday in her first match since making a comeback.
Clijsters said the Brisbane tournament would help her prepare for the Australian Open later this month.
"I'm really happy that I'm here because it really makes the transition to Melbourne a bit easier," she said.
"At least now we have a roof over us and you get a feel for the humidity and you don't all of a sudden come from snow to extreme heat."