Day came into the final day of the series having dropped his first race loss in 10 outings in the penultimate round on Saturday, his first defeat since returning from an 18-month injury-forced hiatus last season.

He still carried a five-point overall series lead into the final day, with only fellow former series champion Matt Bevilacqua capable of reeling him in.

That bid ended before the final race, with Bevilacqua eliminated in qualifying ahead of the final, leaving Day series champion before even answering the final starter's gun.

He ultimately finished third behind in the final race claimed by another former Warilla Barrack Point nipper in Ben Carberry, who claimed his first ever race win.

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Carberry was also first across the line in the earlier race, the 110-kilo former Bureleigh Bears front-rower thriving in the monstrous conditions to edge out retiring veteran Matt Poole in a thrilling sprint finish.

"I am stoked to come away with a win in the last series race, and my first ever series win," Carberry said.

"It was a tough one - you had to slow up and speed up at the same time. To find your way out you really had to go for it and attack it.

"It was really good, it was so exciting out there, and I was just having a lot of fun. I was just hoping my legs would hold up - I knew [Poole] had a bit of pace up the beach.

"I knew it was a race to the first pole, I knew I had to get the inside run, and I just got there. I think I have been in the series for seven years.

"You just keep at it and hopefully something goes your way. Eventually it might, and today was my day."

With his third place, Day finished a staggering 18 points clear atop the series leaderboard and was more than happy to share the final podium with a childhood mate in Carberry, and long-time series rival in Poole.

"I grew up with Benny down at Warilla and he's one of my best mates," Day said.

"And Pooley, I feel like I've been good mates with him forever now, he'll always be one of my heroes. He walks away today with a second place on the podium - it's the fairytale finish for a great career."

Day joins a couple of his idols in Thirroul product Dean Mercer, and series legend Ky Hurst in claiming his fourth crown.

At just 30 years of age, chasing down the likes of Shannon Eckstein, Zane Holmes, Darren Mercer and Trevor Hendy on that list of series wins isn't beyond the Kiama product.

Regardless, the dominance with which he's claimed the past two series - to go with seven Coolangatta Gold wins - puts him comfortably in the pantheon of the sport's greats.

"It hasn't sunk in yet to be honest. It's just a relief that I was able to get through the first race," Day said.

"To finish it off like that, with a third in the final round and an overall series win is great.

"The goal the whole time, since I started in the series, was just to be consistent. I feel like I've been able to do that and that's what has delivered me the series."