Manson was relieved simply to be at the start line after crashing into a car while training on his bike near Cambridge last month.
"I was going about 40km an hour and went straight over the bonnet. Half my bike was on one side of the road and the other half was somewhere else," he said.
"Luckily I didn't hit my head or break any bones as it could have been a season ending injury or worse."
Manson dominated much of this year's international racing until the world championships in Florida in October when he failed to claim a medal.
"I lost about two months of training from sickness and injury" he said.
"I was in really bad shape in Sarasota, and in hindsight was lucky to make the final. It was disappointed because I know how fast I can go when I'm on form."
He wasn't getting ahead of himself after trouncing Drysdale, who has only returned to racing in recent weeks after a long break following his Rio Olympic triumph.
Drysdale, 39, is targeting selection for the Tokyo 2020 Games and will duel with a determined Manson for next year's spot.
"This was a chance to see where I'm at because this regatta's insignificant in the grand scheme of things," Manson said.
"My focus is on world champs and I plan to be in the single for New Zealand but I've got a lot more training to do and I'm going to get a lot faster."
- NZN