Goal hero Anth Ross was the toast of Southwick after his early goal set them on their way to championship glory after beating Victoria Gardens in the Premier Division title decider.
Both teams have had excellent seasons and it boiled down to the final day to decide the champions.
It nearly went pear-shaped for Southwick after Anthony Stokell saw red, but it never fazed the hosts as Ross came up trumps with a fine strike.
Gardens had their chances to stay in the game, but they could not breach Suddick’s defence.
The clincher came when man of the moment Jamie Fairley’s pace got him beyond the back four to fire hard and low into Ryan Graham’s bottom corner to seal victory and the title for Southwick.
Paul Kane starred for Southwick, with Paul Wardle best for Vics.
Southwick go for more glory tomorrow when they tackle Ryhope Foresters in the Joe Holborn Memorial Trophy final at Ford Quarry (10.30am kick-off).
SR Dons took advantage of their man advantage to run out 4-3 winners against RCA Grangetown Florists.
Florists had Shaun Petch red-carded, but still had Simon Hepinstall (2) and Jordan Harkness on target.
Dons finished the stronger, though, with Reece Huntley hitting a stunner, followed by a brace from Lewis Carman. Super sub Michael Laws then made sure of a dramatic victory.
Jack Pearson shone for Dons, with Mark Robinson best for Florists.
The runners-up spot in Division Two was decided in the final game of the season.
The Park were heavy favourites, but Pennywell Comrades were fired up after going into the game, licking their wounds from their cup final defeat.
Pennywell struck first through Jon Greener, and they remained ahead at the break, thanks to some excellent saves from Comrades’ man of the match, Craig Chapman.
The Park looked even more dangerous in the second half, but Greener hit his second with a great strike after a flowing move, then Keiran Harrison lobbed McDermott from 40 yards to make it 3-0.
Lewis Fairley got in on the act as he despatched a dubious penalty and Dan Pattison struck a fine effort to make it 3-2.
That ensured a tense finish as The Park only needed a point, but Pennywell held on for the win to take the runners-up trophy behind champions Grange Park.
Connor Gales stood out for Park.