Defending champions Hampshire Hawks were bowled out for 74, their lowest ever T20 Blast score, as they were thrashed by eight wickets at Somerset.
Craig Overton starred with 3-8 with the ball and four catches as Hampshire were dismissed in the 17th over.
Kent Spitfires, winners in 2021, opened their campaign with a comfortable seven-wicket win over Gloucestershire.
And in the North Group, Worcestershire Rapids posted 196 to beat Northamptonshire Steelbacks by 15 runs.
Hampshire began last season’s T20 Blast with four successive defeats before winning 12 of their last 13 games as they claimed the trophy with a dramatic one-run win over Lancashire Lightning in the final.
That run also included victory over Somerset in the semi-final on Finals Day at Edgbaston. This time around the hosts completely outplayed their opponents at Taunton after asking the visitors to bat first.
The new ball pairing of Overton and New Zealand pace bowler Matt Henry ripped through Hampshire’s batting as they slipped to 12-3 off four overs.
Overton then took two wickets in the seventh over to reduce the visitors to 27-5 and the England bowler finished off the innings with two stunning catches in the deep as Hampshire knocked 11 runs off their previous lowest T20 score of 85, set back in 2008.
Somerset then only required 9.3 overs to reach their target of 75 with wicketkeeper Tom Banton scoring 40 off 24 balls at the top of the order.
At Canterbury, Gloucestershire looked well set at 72-2 after choosing to bat with opener Chris Dent racing to a half-century off 26 balls.
But when he departed for 55 to make it 82-4, the innings subsided as Kent took the last seven wickets for 31 runs. After Dent, the next highest score was 12.
They were all out for just 113 with more than three overs to spare, with the evergreen Michael Hogan the pick of the bowlers with 3-13 off three overs.
That total always looked too small and a second-wicket stand of 52 from Daniel Bell-Drummond and Joe Denly put Kent in a strong position.
The left-arm spin of Tom Smith held them up a little bit as he claimed 3-22 from his four overs, but some lusty hitting from Jordan Cox with 38 not out from only 16 balls saw Kent home with 39 balls to spare.
Having only won three of their 14 matches in finishing bottom of the South Group last season, it was a good start to rectifying that for the Spitfires.
Worcestershire Rapids lost their opening four games last season on their way to finishing bottom of the North Group, but the 2018 champions began with a fine performance against Northamptonshire Steelbacks.
They opted to bat first and Adam Hose led the way in the middle order with 61, although crucially he was dropped on 43.
However, late impetus was added by Ed Pollock with 23 off 11 balls and Usama Mir with 20 from seven as 52 runs came from the last four overs taking the Rapids to 196-9.
In reply, Northamptonshire’s opening pair reached 50 inside five overs but Australian T20 specialist Chris Lynn was out for 28 just as he was starting to find his stride.
Ricardo Vasconcelos and Steelbacks T20 skipper David Willey, on his first game back after seven seasons at Yorkshire, kept them above the required run rate, but the leg-spin of Pakistan bowler Mir made the difference.
He bowled Vasconcelos for 32 in his first over and took another wicket in his second as Northants slipped from 90-1 to 116-6.
And despite number eight Tom Taylor top scoring with 44 from 26 balls, they ended 15 runs shy of Worcestershire’s score on 181-8.