Karapani scored a late try in the Broncos' 14-12 win over Penrith in Sydney to keep Brisbane's paper-thin premiership defence alive ahead of a trip to Townsville to face North Queensland next Saturday.
Thursday's game was Karapani's first at NRL level since he was dropped by Brisbane's leadership group after he was hit with a drink-driving charge and several driving offences last month.
It was second off-field indiscretion this season that led to Karapani being left out of Brisbane's side with the winger previously having been stood down for a public nuisance order in March.
"They made a hard decision to make me come back from everything that's happened," Karapani told AAP.
"It truly made me feel like I had to give back to the boys and do everything that I could to get the two points.
"They have always backed my abilities in this team and I've had some one-on-ones with the leadership group and that really gave me the confidence to do my best.
"We've got the result and that's all that matters to me."
Karapani is due to face court later this month but is intent on ensuring Brisbane's premiership defence doesn't end in a whimper.
Michael Maguire's men remain a mathematical chance to make the top eight but will likely have to win all of their remaining seven games as a result of their poor points differential.
"There's always been that belief from 'Madge' (Maguire) and he's always given us tips and advice of where we're missing just a little thing," Karapani said.
"This week it feels like we've achieved the goals we've always been striving for.
"Especially getting the win over Penrith with them on a win right now, it's more on ourselves.
"We respect the team we came up against but the belief in our team, we're capable of making something happen."
Meanwhile, Auckland-born Karapani confirmed he was set on representing New Zealand at this year's Rugby League World Cup.
Despite having Samoan heritage, Karapani has no intention of changing allegiance after being called into the Kiwis squad last year.
"It's about loyalty and them wanting in their camp that made me feel wanted," Karapani said.
"They were the first ones to approach me so my loyalty goes towards that group."
