Goals from Alex Joy (3) and Marley Ambler followed up a 3-2 midweek win over Hailsham Town (Rob O'Toole (2), Harry Robins).
The two wins put Mile Oak in sixth spot in the table – with Arundel still ahead of them, in fourth.
"It's been a very positive week, said Mile Oak manager Kieran Ridley.
.”The first half we weren't at the races against Hailsham but we responded brilliantly with a superb second half performance.
"That followed into the opening half of the Arundel game. Our visitors were top of the league when they arrived but we were outstanding first half, coming in 3-0 at the break.
"We were very organised second half and nullified any response before adding a fourth. A late goal was only consolation for Arundel, but overall it was a spot on performance.
"It sets us up nicely for bank holiday weekend. Saturday we head to Westfield before hosting Worthing United on the Monday morning."
Elsewhere in SCFL Division 1, East Preston drew 2-2 at home to Dorking Wanderers while Worthing United romped to a 7-0 win at Oakwood and Shoreham won 2-0 at home to Clanfield.
In the SCFL Premier, Lancing were celebrating their first league win of the season after Mohamed Khedidji, Archie McGonigle and Dylan Walter scored to secure a 3-1 victory at Horsham YM.
See pictures by Stephen Goodger from Mile Oak 4 Arundel 1 on this page and those linked and get all the local football in the Worthing Herald and Littlehampton Gazette, out on Thursday.
9. Mile Oak v Arundel pictures by Stephen Goodger (13).jpeg
Mile Oak v Arundel, SCFL Division 1 Photo: Stephen Goodger
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Mile Oak v Arundel, SCFL Division 1 Photo: Stephen Goodger
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Mile Oak v Arundel, SCFL Division 1 Photo: Stephen Goodger
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Mile Oak v Arundel, SCFL Division 1 Photo: Stephen Goodger