Melbourne Renegades captain Will Sutherland got his T20 Blast campaign with the bat off to a thunderous start in Leeds, but a superb individual display by David Willey has inspired Northamptonshire to a 13-run victory over former club Yorkshire.
The Steelbacks' captain Willey struck 54 and along with Justin Broad's 67 it helped the away side make 4-237 at Headingley on Friday.
Both James Wharton and Sutherland smashed 58 for Yorkshire, but Willey's 3-42 made sure his new team fought back to limit the hosts to 9-224.
Sutherland almost rescued the contest with six sixes and two fours in his 30-ball knock, which included four maximums in a destructive 12th over, before he was out trying to slog another boundary off fellow Australian Lloyd Pope, the legspinner who claimed 2-37 off his four overs.
Elsewhere, Zak Crawley played his part in an explosive Kent batting display which was enough to ensure visiting Gloucestershire started the defence of their crown with a four-run loss.
Crawley smashed four sixes in a rapid 37 from 17 balls while Daniel Bell-Drummond top-scored for the Spitfires with 60 in an imposing total of 3-208 in Canterbury.
It proved too much for Gloucestershire but only just as late hitting by Ben Charlesworth (38) revived their hopes before 2-22 by Canberran Tom Rogers made sure the champions got their South Group campaign under way with a defeat after being restricted to 7-204.
Somerset won a repeat of last year's semi-final with Surrey despite a fine innings of 92 by former England opener Jason Roy in a total of 9-146.
Overseas pace duo Matt Henry and Riley Meredith claimed three-wicket hauls for the 2024 runners-up, who won by five wickets with 13 balls to spare after Will Smeed (35) led the way at the top of the order.
Liam Dawson had Essex in a spin to help Hampshire record a thumping 106-run victory at Ageas Bowl.
James Vince (62) was one of three Hawks batters to pass fifty and it helped his team post a mammoth 7-230.
Michael Pepper struck 51 for Essex before falling to Dawson (4-26).
Birmingham topped North Group last year but started this season with a seven-wicket loss to Nottinghamshire.
Sam Hain's unbeaten 92 proved the bedrock of Bears' 5-226, but he was outclassed at Trent Bridge by Jack Haynes.
Haynes blitzed 89 not out from 41 balls, with 11 fours and three sixes, to lead the Outlaws home in the final over.
Derbyshire made 6-170, but were indebted to 70 down the order from Martin Andersson after 3-37 from Leicestershire's Logan van Been had them reeling on 5-51.
A mature innings from Pakistan captain Shan Masood (45no) endured the Foxes chased their target five down with Pat Brown smashed for 47 off his 2.4 overs.
With AAP.