Arrambide's long-awaited QS win came on home soil with huge performances over event standouts throughout finals day.
The final day of competition will decide regional QS champions.
Opening day at the first-ever WSL event held on Pismo Beach's shores soared through Round One action and witnessed top seeds debut in Round
One last event will determine who boasts the North America Regional men's QS Title by Sunday.
The inaugural Pismo Beach Open QS1,000 will be the final deciding factor for who takes the North America Regional Title.