"It was a good tough fight and he definitely made me work for the win," he said.
"The secret to beating [Carroll] was finishing strong in the last three rounds. That was the turning point as the fight was so close.
"My defence was pretty tight because he was throwing some nice hard body shots. I am feeling a bit sore over the whole body but am stoked with the win."
Jackson says his next bout could be a match-up with highly-rated Australians like Les Sherrington or former IBF World Middleweight champion Sam Soliman.
"They are the next top Aussie guys I am looking to challenge. First I am going to take a week off training and clear my head a bit and see what the next opportunity arises. I will have a talk with [trainer] Chris Walker and manager Craig Thomson to see what is in the pipeline."
Walker says beating Carroll is a significant win for Jackson as the tough Australian has a decent pro record.
"You have to be pretty good to win an Australian middleweight professional title and he had only two losses before Saturday," said Walker. "It was a good fight for Gunnar as regards to getting 10 good rounds under his belt against a hearty sort of opponent.
"Gunnar's last two fights he stopped both opponents so he had a harder fight this time. All his performances in his last four fights have been great and puts him in the mix for a chance of a championship shot."
Walker and promoter/manager Craig Thomson are hopeful of securing Jackson's next title defence in Tauranga later this year.