The hosts failed to chase down Chilt’s total of 126 as they fell to a 46-run defeat in the derby clash.
Asked to bat first, the visitors really struggled to post a sizeable total with only three batsmen making double figures and youngster Ben Lucking (58) was the only player on either side to make a half century.
Steyning debutant Jack Manvell, 15, impressed with the ball, picking up figures of 4-35.
Chilt’s total of 126 all out looked to be eminently getable but Steyning also struggled from the off in the face of some good fast bowling from Reuben Taylor and overseas player Mithelesh Rawat.
Chilt spinners, Hugo Gillespie and Lucking, kept the pressure on with Alex Miller also bowling in a rare run out this season.
Three Steyning batsmen also made double figures but none passed 20 as they folded to 80 all out.
With Slinfold losing to new champions Goring, both sides now know they will be playing Division 3 cricket next season.
Steyning skipper Luke Chapman said: “It was a frustrating batting performance by us. To bowl them out for 126 was a great effort. It’s a real shame we couldn’t knock of the runs and get the 30 points I thought we deserved.
“Young Jack Manvell, 15, on his first team debut, was superb. To get four wickets on his debut was a great effort and he should be really pleased with himself.
“At the start of the season the aim was to stay up, to achieve this is really pleasing. We’ve given some of the younger guys a chance to perform this year and they really have stepped up. Overall it’s a been a very enjoyable season.”
Despite three consecutive league wins, Chilt 2nd are still not completely safe after a home defeat to promotion chasing Rustington.
Home captain Josh Reeves was playing against several relatives in a good natured match where another Chilt batting collapse featured heavily. Batting first, the visitors were dismissed for 180 in the 35th over. Paddy Chapman made 64 with Jon Denton taking 3-20.
In reply, Chilt were 76 when the second wicket fell which started the collapse. They were all out for 108 after 39th overs. Bhavesh Prabhakar took 4-24 and Chilt keeper Charlie Tear made 57.
The under-19s lost their last two group games - at Cuckfield and at home to Horsham - to finish runners up in the North Area Group.