The England all-rounder ended a month which had already brought him a first-class best 187 on the same ground, a Yorkshire Bank 40 century against Kent and a half-century in a Twenty20 international with 81 from 49 balls to lead the Sharks to an imposing 202 for three from their 20 overs.
He was well supported by captain Chris Nash (45), Rory Hamilton-Brown (47) and Dwayne Smith (21 not out) as the seven bowlers used by the hosts all came in for some punishment. Dawid Malan (61) and Paul Stirling (33) got a testing chase off to a quick start and captain Neil Dexter hit three sixes in a defiant 27 from 10 balls but it was not enough for the hosts, who finished on 178 for eight - which included six penalty runs for Sussex's slow over-rate - as Michael Yardy took three for 30.
Surrey beat Kent by 31 runs for their second victory in the competition, Steven Davies leading the way with an unbeaten 95 in their total of 176 for three.
Davies put on 66 with Jason Roy (16), 47 with Ricky Ponting (19) and 57 with Glenn Maxwell, who hit 32 from 18 balls. The only slight frustration for the former England wicketkeeper would have been his inability to get on strike in the final over with three figures so close, though Maxwell and Azhar Mahmood took 18 from it as the latter hit his only ball for six.
Sam Northeast (61) and Darren Stevens (30) gave Kent hope but they were pegged back, Jade Dernbach taking three for 22 as they finished on 145 for nine.
Michael Klinger smashed a brilliant 61-ball century to lead Gloucestershire to a 48-run victory over Worcestershire at Bristol in the Midlands, West and Wales Group.
The skipper cracked five sixes and nine fours in contributing 108 to the home side's total of 184 for five after winning the toss. The next highest score was Alex Gidman's 18 as left-arm spinner Shaaiq Choudhry claimed one for 13 from his four overs.
In reply Worcestershire could muster only 136 all out, Alexei Kervezee making 39 and Ben Cox 37 from number eight. James Fuller (three for 23), David Payne (two for 14) and Benny Howell (two for 28) all bowled tightly for Gloucestershire.
Yorkshire suffered a second successive defeat in the North Group, losing by four wickets to Durham at Scarborough. The Tykes were grateful to some late hitting from Liam Plunkett, as the former Durham paceman's 30 from 16 balls lifted them to 146 for seven. But Phil Mustard made 59 and Gordon Muchall hit 44 not out from 27 balls as Durham got home with a ball to spare, Plunkett conceding 16 runs in the 19th over.