Tom Edwards’ double won it for Billingshurst, with Harry Russell on target for the Mullets.
Forest Row are the early leaders in the division after starting with a 6-0 win at home to Banstead.
See pictures by Stephen Goodger from Arundel-Billingshurst on this page and the ones linked – and get the local football action in the Worthing Herald, Littlehampton Gazette and West Sussex County Times, all out on Thursday.