Trevor-Roper showed great heart against the bigger and more powerful Parson during the overall title bout, but eventually succumbed and provided Parson with his fifth overall national title in a row.
"It was a great display of technique and power proving size is not everything," Parson said of Trevor-Roper's performance.
Meanwhile, fellow River City fighter Brian Alderton put on another good display of strong hand work to wear down his opponents and win back the middleweight title for the second time.
Alderton has also claimed an Australian middleweight crown.
"Brian had been training hard and it showed in his confidence to put the pressure on early in the fights and as a result came away with the fastest knockdown of the tournament," Parson said.
Trevor-Roper put on a clinical show to win his lightweight division. And now having won back the lightweight title he will look to move up a weight class next year.
A suspected broken foot ended Wanganui's Richard Hood's progression after coming up against clubmate Chris Sheahon.
Sheahon fought well and won his first fight before coming up against Hood.
He fought valiantly and put up a good fight, but in the end Hood's devastating leg kicks got the better of him.
Hood ended up with a suspected broken bone in his foot meaning he couldn't continue.
Other Wanganui fighters Aweri Blakely, Sam Laurie and Samantha McMillan lost their first fights, but showed good spirit and grit in trying their hardest and leaving everything on the mat gaining valuable experience.
Parson said the domination by Wanganui Kyokushin Karate and Wanganui Warriors Kickboxing competitors was a result of the high level of trainers and training systems.
