Worthing eased through with a 76-run win at home to Stirlands. Worthing posted 136-4 from their 20 overs as Matthew Green hit 54 and Andy Reid 46.
Stirlands were then restricted to 60-9 as only Struan Cameron, with 35, reached double figures. New overseas player Corey Altis, Jamie Piper and Mason Crane all took two wickets.
Bexhill progresed with a 86-run victory over Rye.
Shawn Johnson struck 54 and Max Finzel 45 as Bexhill scored 146-5.
Rye were dismissed for just 60 in their reply as Jamie Bristow-Diamond took 5-5 from three overs.
Brighton & Hove cruised past Hellingly with a 131-run victory.
Paul Hardwick smashed 66 from just 35 balls, with six fours and five sixes, as Brighton scored 182-5.
Hellingly scored 51-8 from their 20 overs as Matthew Wood and Christopher Atherton took two wickets each.
Lindfield overcame Cuckfield by 52 runs as Rob Keen hit 59 in their total of 138-6.
Cuckfield were restricted to 86-9 in their reply as James Aggio-Brewe claimed 3-10.
Horsham won by three wickets away to Slinfold.
Akeem Jordan fired 51 not out as Slinfold scored 107-7, before Horsham got home with a ball to spare.
Horsham were 45-6 before Elliott Cloy struck 31 and Dave Castle 22 not out to help get them home.
St James’s Montefiore reached the second round with a 30-run success against Crawley.
Jack Foreman top-scored with 44 not out as St James’s scored 137-5.
Crawley replied with 107-6 as Foreman took 2-18 from three overs.
Ifield eased through with a 48-run victory against Burgess Hill. Ifield scored 117-7, before Burgess Hill were all out for 69.
Portslade’s first match in the Sussex League ended with a 57-run defeat at Eastbourne.
Eastbourne skipper Callum Jackson smashed 102 from 67 balls as his side posted 168-2.
Portslade were all out for 111 despite 62 from Sam Delaney, who hit five fours and four sixes.
Luke Gallichan took 3-19 and there were two wickets each for David Twine and Joe Barnett.
Keymer & Hassocks won by four wickets away to Haywards Heath after the hosts were all out for just 87.
Keymer reached their target with one over to spare.
Preston Nomads began their season with a two-wicket victory at Middleton.
Will Burrows hit 39 not out as Middleton posted 107-6. Nomads reached their target with two wickets to spare.
East Grinstead won by 51 runs at home to Three Bridges.
The hosts scored 118-6, before Bridges were all out for just 67. Sam Jewiss took 4-9 for East Grinstead from his four overs.
Roffey progressed past Pagham 5-4 on a bowl-out in their first round clash.