The world number one was denied by Michael van Gerwen in the Queensland Darts Masters final a fortnight ago, but he made amends to sign off in style in New Zealand.
Clayton was bidding to make it back-to-back World Series crowns following his win in Wollongong last weekend and he started strongly, with an 11-dart hold in leg four sparking a sequence of three straight legs.
However, Price pinned double five to stop the rot in a crucial seventh leg, and he was indebted to the same target moments later, closing out a 12-dart break to restore parity at 4-4.
The 2021 world champion continued his charge with legs of 15, 14 and 15 darts to move 7-4 ahead, and after Clayton fluffed his lines on the outer ring, Price converted a clinical 92 kill on double 12 to complete the comeback.
“It feels fantastic,” said Price, celebrating his 26th PDC title and his second World Series of Darts triumph.
“Fair play to Jonny. I think he upped his game in the final, but thankfully I improved after the break and showed why I’m world number one.
“I think I was quite fortunate to win the last leg before the break, and I knew if I upped my scoring game I would have a chance.
“The crowd were absolutely awesome. They supported both of us tonight and they were magnificent. Thank you New Zealand!"
Price began Saturday’s action with an emphatic 6-2 win over James Wade, avenging his defeat against the left-hander in last weekend’s NSW semi-finals.
The Welshman then produced an impressive display to oust top seed Dimitri Van den Bergh in the last four, winning six out of the last seven legs to complete a 7-4 win over the Belgian.
Clayton was unable to secure his second successive World Series victory, but he dumped out defending champion van Gerwen in a heavyweight quarter-final tussle.
The former Premier League champion averaged 98 and landed two ton-plus checkouts to record a convincing 6-3 win over Van Gerwen, who trailed 5-1 at one stage.
The 47-year-old then stormed into Saturday’s showpiece with a battling 7-5 win over Michael Smith, producing a classy display of combination finishing to defeat the St Helens star for the second straight event.
“Gezzy is lucky I missed those three darts at double 18,” quipped Clayton, the reigning World Series Finals champion.
“Fair play to Gerwyn. He came out of the blocks after the break and I can have no complaints. He was fantastic.
“I have loved every second of my time in New Zealand. We had two Welshmen in the final, and I thoroughly enjoyed it.”
New Zealand Darts Masters results
Friday August 26
First Round (Best of 11 legs)
Evening Session (1900 local time, 0800 BST)
- Jonny Clayton 6-1 Mal Cuming
- Joe Cullen 6-2 Damon Heta
- James Wade 6-5 Gordon Mathers
- Fallon Sherrock 5-6 Kayden Milne
- Michael Smith 6-3 Warren Parry
- Michael van Gerwen 6-3 Bernie Smith
- Gerwyn Price 6-3 Ben Robb
- Dimitri Van den Bergh 6-4 Simon Whitlock
Saturday August 20
Evening Session (1900 local time, 0800 BST)
Quarter-finals
- Dimitri Van den Bergh 6-5 Joe Cullen
- Gerwyn Price 6-2 James Wade
- Jonny Clayton 6-3 Michael van Gerwen
- Michael Smith 6-0 Kayden Milne
Semi-finals
- Gerwyn Price 7-4 Dimitri Van den Bergh
- Jonny Clayton 7-5 Michael Smith
Final
- Gerwyn Price 8-4 Jonny Clayton
Fast Results
Scores
Racecards 
