Roffey put Brighton in, and the visitors posted 46 for the first wicket, but soon found themselves 52-3 after both openers were dismissed in quick succession.
Tim Jarvis (48) staged a steady recovery with wicketkeeper Adam Mates – who ended unbeaten on 60 - but a cluster of late wickets enabled Roffey to contain Brighton to 206-7 from their 50 overs, Luke Barnard and Leigh Harrison each taking two wickets.
Replying, Roffey set off in a hurry with Rohit Jagota again taking full advantage of the power play, his 34 ball 46 containing four fours, and three sixes peppering Northolmes School and neighbouring gardens.
Josh Fleming, batting at three made 37, but a mid order wobble reduced the hosts to 148-6, and with 59 still needed, it took 39 not out from George Fleming to get Roffey across the line, finalising victory by three wickets with just over 11 overs to spare, Brighton avoiding the drop by four points.
A full scorecard from the game can be found here.
With 11 wins, Preston Nomads CC won the league for the first time in eight years, with East Grinstead CC as runners up, while Cuckfield CC, despite beating Nomads, skittling them for 114, were relegated, along with wooden spoonists Haywards Heath CC, returning to Division 2 after just one year back in the Premier Division.
Roffey skipper Matt Davies told the County Times: “Finishing third was a fair assessment on how we performed and the teams we had out.
"There were odd games that we might have wrapped up when it was wet, but we can’t do anything about the weather, and we lost to Nomads and Grinstead, so we’ve got no complaints.”
Davies continued: “We’ve come a long way in the past few years, so naturally we’re a bit disappointed, and we want to get back to challenging in the league and cup.
"We’ll be assessing where we need to strengthen – if we can build up the firsts that’ll help the seconds, too.
"There have been some real positives – Rohit Jagota has been great again, and Theo Rivers has come good with three tons.
"Also, Harnoop (Kalsi) has bowled well, and Sam Henderson has been superb: he’s got a great future, and its been great to blood some of the other young players – we’ve had a good season from that standpoint.
"And, among the seniors, Leigh Harrison has been a diamond. We’re still hungry for silverware, so this season will motivate us!”