The Pontyberem product, who is back in the tournament after missing out on selection to the last two campaigns, beat the world number three in the final 6-2 to continue his impressive start to the year.
He started the night by ending a near three-year and 10-match losing run against compatriot Gerwyn Price, before demolishing world number one Littler 6-1 in the semi-finals.
The 2021 winner averaged 99.88 and 101.33 in those two matches, but it was his checkouts at 60% and 66.67% that really stood out.
While that dropped to 42.86% in the final, his average increased to 104.35 as he follows Price and Michael van Gerwen as night winners this season.
He broke Van Veen in the opening leg and in the seventh before sealing victory with a stunning 156 checkout.
The victory takes him to the top of the early standings, ahead of Van Gerwen, who missed the night through illness, and Van Veen, who has now been beaten in two finals.
Speaking to Sky Sports after the conclusion of the night, Clayton said:
“I felt good tonight. Didn’t expect the 6-1 against Luke, I’ve got to be honest. I felt good, my darts are going. When your finishing goes good the confidence goes up.
“Like I always say, if I don’t succeed today, I’ll try again tomorrow. When you take your chances, it makes a hell of a difference. To get Gezzy [Gerwyn Price] off my back, that was a big thing for me.
“I had a chance last week and just couldn’t finish it. It’s obviously in the back of my mind thinking ‘when am I going to beat my buddy’. We’re great friends, he’s a brilliant darts player. Tonight was my night.
“I’m enjoying myself and when you enjoy what you’re doing things seem to happen in you. I’ve got a bit of experience in this tournament, it’s my favourite tournament, and I know what I have to do to get to finals night.
“I don’t like it that I’m the oldest in there, I’ve got to be honest! It’s nice to see different faces; it’s nice to see the young guns. I’m enjoying myself, but I’ve got to concentrate on myself, not them. I’m doing alright so far.”
