Matt Parkinson’s hat-trick helped Kent rout Middlesex by 98 runs in their Vitality Blast opener at Chelmsford.
Parkinson removed Jack Davies, Tom Helm, and Henry Brookes in the third over on his way to figures of four for 25, with the hosts bowled out for just 107.
Kent had made 205 for eight from their 20 overs, with Joe Denly making 56 from 33 balls.
Tom Abell and Lewis Gregory helped champions Somerset start the defence of their title with a four-wicket victory over Essex.
Abell made 55 from 36 balls and Gregory added 44 from 22 as Somerset reached their target of 194 with five balls to spare in a repeat of last year’s final.
Dean Elgar made 77 from 51 as Essex posted 193 for six.
David Willey powered Northamptonshire Steelbacks to their second win from two, crushing the Notts Outlaws by eight wickets.
Captain Willey hit seven sixes and seven fours in a 34-ball 79 as the Steelbacks made light work of reaching their target of 155, winning with 40 balls to spare.
Joe Clarke and Jack Haynes shared a 95-run partnership as they reached 104 for one from 10 overs, only to collapse as they lost their last nine wickets for 50 in 9.2 overs, with left-arm spinner Saif Zaib taking a career-best three for 12 in three overs.
Jamie Smith smashed eight sixes in an explosive innings of 76 that set Surrey on their way to a 19-run victory over Glamorgan.
Smith helped Surrey to 200 for eight from their 20 overs, and that proved too much for Glamorgan despite half-centuries from Marnus Labuschagne and Colin Ingram.
Ingram was guilty of putting down Smith when he was on 20 off the bowling of Mason Crane – and was made to pay the price.
Sussex scrambled a bye off the final ball to take a three-wicket win over Gloucestershire at Hove.
Chasing 168, Sussex needed 10 off the final over. Fynn Hudson-Prentice, having led the charge, fell for 47 but Jack Carson then hit a six and nicked a single.
Nathan McAndrew failed to make contact on the final ball but James Bracey missed the stumps as Sussex snatched the win.
Brett D’Oliveira’s half-century helped Worcestershire Rapids to a five-wicket win over Lancashire Lightning at New Road.
Chasing 170 to win, D’Oliveira made 61, helping to steer the Rapids to within 22 runs of victory before Tom Taylor finished the job, hitting a six in the final over to win it.
Lancashire had been rocking when reduced to 13 for three in the early going, but captain Steven Croft made an unbeaten 52 to help them to 169 for five.
Leicestershire Foxes romped to a seven-wicket win over Yorkshire Vikings as Sol Budinger plundered 50 runs off 22 balls.
Josh Hull took three for 28 as the Foxes held Yorkshire to a modest 151 for seven, and the hosts wasted little time in chasing that down.
Budinger teamed up with Rishi Patel as the openers hit six sixes and six fours in the first five overs, making 79 off 36 balls to leave little doubt about the result.
Hasan Ali and Richard Gleeson led an outstanding performance from the Birmingham Bears’ attack as they beat Durham by six wickets at the Riverside.
The experienced seamers took five wickets between them as Durham were bowled out for just 101, continuing the batting woes seen at Lancashire on Thursday.
Sam Hain made an unbeaten 27 as Birmingham chased down their target in 16.1 overs.