Sussex 150 for 1 (Salt 78*, Wright 56) beat Glamorgan 146 for 9 (Lloyd 50, Topley 3-20) by nine wickets
Sussex's fifth win out of six - they also tied against Surrey - moved last year's beaten finalists above Kent Spitfires and they were always in control against a Glamorgan side still looking for their first win of the campaign.
After they restricted Glamorgan, who won the toss, to 146 for 9, openers Luke Wright and Philip Salt launched the reply with a withering assault which brought 130 in 12 overs, Sussex's fourth highest partnership in the format and their biggest against Glamorgan.
The pair rattled along at more than ten an over from the start, matching each other shot for shot against a toothless Glamorgan attack which lacked variety compared to Sussex. Salt reached his fifty with a six into the top tier of the pavilion off Andrew Salter and the offspinner was hit for boundaries off the next two deliveries.
Salt won the game off the fifth ball of the 13th over with an uppercut over third man which brought him his eighth boundary, he also hit three sixes as he finished on 78 not out from 42 balls - his third half-century of this season's competition.
It looked as if the Sussex pair might win the game on their own but Wright fell to a superb diving catch in the 13th over by wicketkeeper Chris Cooke after making 56 off 35 deliveries with five fours and two sixes. There were 6.1 overs left when Sussex eased to victory.
Such a one-sided contest had seemed unlikely with Glamorgan in good shape at 55 for 1 in the ninth over and opener David Lloyd going well. But they lost eight wickets for 87 and were never the same after Lloyd departed to the next ball after reaching his second fifty of this season's Blast.
The 27-year-old hit nine fours from 37 balls faced but he holed out to deep midwicket to give left-arm spinner Danny Briggs his second wicket and Glamorgan struggled for momentum thereafter against some accurate and disciplined Sussex bowling. Skipper Colin Ingram, Kiran Carlson and Chris Cooke all threatened but Sussex maintained a happy knack of taking a wicket just when Glamorgan threatened to put together a decent partnership.
Briggs was taken for 18 in his final over and Tymal Mills' last over cost 11 runs, but Glamorgan lost wickets too regularly to build any momentum and set a challenging total. Ollie Robinson removed Graham Wagg and Cooke with successive balls in the 17th over and finished with 2 for 27 but the pick of their bowlers was Reece Topley, who finished with 3 for 20. Sussex's fielding was excellent with Salt taking two superb diving catches in the deep to complete an excellent evening.