Roffey cut leaders Preston Nomads’ advantage at the top of the Premier Division to just five points as they climbed up to second on Saturday.
The champions made fairly simple work of a five-wicket win as, batting second, they knocked off Eastbourne’s 153.
The home side, having been inserted, lost Callum Jackson early for three, before captain Luke Tomsett was forced to retire hurt.
He had scored two runs before he ducked into a length ball and was taken to hospital.
Dan Wells battled his way to 30 before he was trapped lbw from Ben Manenti’s bowling.
Eastbourne struggled to gain any momentum with the bat and only David Twine (72) made a telling contribution before he was caught by Chris Webb from Rohit Jagota’s bowling.
Leigh Harrison (3-27), Manenti (2-53) and George Flemming (2-18) led the attack.
Chasing a small target, Roffey were off to a solid start with captain Josh Fleming hittng 40 and Mike Norris’ 53 not out.
They comfortably reached their target in the 34th over for the loss of five wickets. Eastbourne bowler Ben Barter claimed 2-14.
Fleming said: “It was a very good win Saturday as we know Eastbourne do not lose many games at home.
“Leigh and Stu bowled beautifully up front to give us the early wickets we needed and they were backed up well by George and Ben.
“It was a good effort in the field to keep them to 153.
“We chased it down relatively easily despite losing a few cheap wickets near the end and Mike Norris played really well to see us home.”
Roffey also won in the ECB National Knock Out Cup on Sunday. Report in Thursday’s West Sussex County Times.