"Jason is a tough opponent," Parker said afterwards. "He came strong, he came ready.
"I tried my best to listen to what people say. I still make mistakes, but it was a good performance. I'm happy with the win and to be able to do it in Samoa."
Trainer Kevin Barry said: "I thought Jason Bergman gave a terrific account of himself. He really came to fight. We wanted a real fight and a real test and Joe got it tonight."
Parker, who looked eager to put on a good performance in front of a big home support, said: "It's an amazing feeling having people support you like that. Thank you Samoa."
The victory was Parker's 18th - 16th by way of knockout - in an undefeated professional career.
Bergman began well, catching Parker with a left lead and then taunting his opponent after being walked back into a corner. He caught Parker again with a head shot seconds later, but the New Zealander began to find his range to the body. Bergman, undaunted, shook his head.
Parker put Bergman down with a left hook to the head 55 seconds into the second round, the American rising before the eight-count.
Parker forced Bergman to a knee with a powerful left hand to the body with 24 seconds remaining in the seventh round but couldn't finish him off.
The Kiwi, warned for hitting Bergman in the back of the head in the fifth round, sent him staggering backwards in the fourth, a right hand to the head which prompted chants of "Parker, Parker" from the crowd.
Parker apparently wore plenty of shots in training for his first fight against a southpaw and he wore some here, although after the first round they carried little power. However, there was a wildness to some of his shots.
The American has enjoyed some wonderful hospitality here in Samoa's capital ahead of the event tagged The Rumble in Paradise, and his welcome on the short walk to the ring at the Faleata sports complex from the 2000-strong crowd was a warm one.
The win allowed the 24-year-old New Zealand-born Samoan Parker to retain his WBO Oriental and WBO Pan African titles as he stays on track on his road to a world title shot.
His ability to flick the switch from almost horizontally laid back to fight mode is one of his special qualities and will stand him in good stead for the tougher tests to come.
Earlier in the day - just over four hours before he took the ring - he wandered around his beach-side resort with his shirt off saying how much he was looking forward to dinner.
Parker's victory, in front of Prime Minister Tuilaepa Aiono Sailele Malielegaoi and head of state Tui Atua Tupua Tamasese Ta'isi Efi, was the culmination of a successful week for him, but also promoters Duco and boxing in Samoa.
Most involved in the weigh-in in front of the government building on Apia's main street following a parade will remember it for a long time, with Parker saying he was glad so many in his entourage filmed it for him to look back on.
Film buff Bergman might even be happy to watch it himself some time.
- By Patrick McKendry in Apia
