Usman Afzaal set Surrey Brown Caps up for a convincing 67-run Friends Provident Trophy victory under the Hove floodlights by slamming a classy unbeaten 126 from 105 balls.
Surrey's 346 for three - a Hove record in this competition - proved beyond Sussex Sharks, who were never in contention and closed on 279 for eight with Afzaal taking 2-4 with his left-arm spin.
Afzaal claimed the wickets of Murray Goodwin (38) and Carl Hopkinson (21) to leave Sussex with only one win from their opening four games in the South East Division.
Sussex needed another big innings from skipper Chris Adams but he was sent back by Chris Schofield for 40, and Mike Yardy also got a start before falling to Matt Nicholson for 39 with nine overs remaining.
Robin Martin-Jenkins ensured that Sussex at least avoided being bowled out by hitting an unbeaten 39.
Afzaal had earlier powered Surrey to their imposing total by compiling a dozen fours and two sixes in his fluent innings.
The 30-year-old former England batsman shared in a third wicket stand of 153 in 23 overs with Mark Ramprakash (63) before Alistair Brown (40 not out) joined him to add an unbroken 87 in the last nine overs.

Mark Ramprakash continued his form © Getty ImagesBuy this photo Ramprakash had stroked six fours in his 80 balls when he was bowled by off-spinner Ollie Rayner.
Surrey, who won the toss on a flat pitch, were given an ideal start with James Benning (51) and Scott Newman (43) sharing an opening stand of 81 in a dozen overs.
Newman drove loosely at Martin-Jenkins to be caught at mid-off before Benning, after cracking eight fours from 48 deliveries, fell to a low return catch by left-arm spinner Tom Smith.
Former West Indies Test pace bowler Corey Collymore struggled to make an impact on his Sussex debut having been signed as a Kolpak registration on a one-year contract.
The 30-year-old, drafted in to add some firepower to the seam attack, finished with 0-71 in nine overs, his first spell of six overs costing 42.
Surrey pace bowler Jade Dernbach (3-56) then struck two early blows by removing Chris Nash and Ollie Rayner cheaply to reduce Sussex to 42 for two.
Opener Andrew Hodd was later pinned in front by Australian pace bowler Nicholson and Sussex's hopes received a big blow when skipper Adams - centurion in the previous win over Middlesex - drove spinner Schofield to mid-off having made 40.
The slide continued with veteran former Zimbabwe star Goodwin being stumped off left-arm spinner Afzaal, who later bowled Hopkinson as he tried to cut to earn him the man-of-the-match award.
Usman Afzaal hoists Ollie Rayner for six © Getty Images