Nottinghamshire batsman Joe Clarke scored an unbeaten century to lead the Outlaws to a six-wicket win over Durham in the T20 Blast.
Clarke hit a six to bring up his ton and clinch victory with 22 balls left.
Paul Stirling starred for Northants Steelbacks in their nine-wicket win at Worcestershire, while Glamorgan beat Gloucestershire by 15 runs.
Middlesex and Kent tied at Lord’s, with the visitors denied in their run-chase in a match which saw 418 runs scored.
Rain had washed out all bar one match from the first round of group fixtures on Thursday and Friday, but most counties had better luck with the weather on Saturday.
However, Lancashire were unable to add to their opening-day win over Durham after their game at Leicestershire was abandoned.
Lightning bowler Tom Bailey took a T20 career-best 5-17 as the Foxes posted 150-9 before the rain set in during the innings break.
In the other North Group match, Graham Clark (60) and Alex Lees (53) helped Durham to what appeared to be a strong total of 181-3 against Notts at Emirates Riverside.
The visitors lost Alex Hales early in their chase but Chris Nash (55 off 29) and Clarke steadied the ship.
Clarke was dropped on eight by Clark and the 24-year-old made Durham pay, hitting seven fours and eight sixes in his 44-ball century to steer Nottinghamshire to a comfortable win.
Stirling inspires Steelbacks
Ireland international Stirling had a debut to remember for Northamptonshire with ball and bat at New Road.
The 29-year-old took 2-26 as Northamptonshire’s spinners restricted Worcestershire to 124-7, with teenager Jack Haynes top-scoring for the Rapids with 41 on his T20 debut.
The Steelbacks made short work of the chase against the 2018 champions, with Stirling crashing nine fours and four sixes in his 48-ball knock of 80 not out.
Elsewhere in the Central Group, Chris Cooke and Andrew Salter were the key men in Glamorgan’s win over Gloucestershire.
Captain Cooke contributed 51 not out as the visitors reached 150-7 at Bristol, and off-break bowler Salter (4-20) demolished the Gloucestershire top order as the hosts slumped to 40-5.
Graeme van Buuren’s half-century gave Gloucestershire hope, but the all-rounder was run out in the final over to put the game beyond his side.
Dramatic finale at Home of Cricket
There was a high-scoring contest at Lord’s as the north London ground hosted its first match of 2020 following the coronavirus lockdown.
Middlesex scored 209-4 in their innings, with opener Stevie Eskinazi notching a T20 career-best 84 and Nick Gubbins contributing 53 from 33 balls.
Kent reached 85-0 at the end of the powerplay but lost momentum once England international Zak Crawley (31 from 19) and Daniel Bell-Drummond (72 off 32) departed.
Yet, needing five runs from the final over to win, the Spitfires looked on course for victory – especially after a bye and a wide from Tom Helm’s first two deliveries.
But the seamer responded by removing Grant Stewart and bowling two dot balls, leaving Kent requiring two to win from the last ball.
Jack Leaning could not get bat on ball and wicketkeeper John Simpson’s throw at the stumps was wayward as the visitors ran a bye to share the points.
Sunday’s fixtures (all start times BST):
Cardiff: Glamorgan v Birmingham Bears (1400)
Northampton: Northamptonshire Steelbacks v Somerset (1400)
Headingley: Yorkshire Vikings v Derbyshire Falcons (1400)
Kia Oval: Surrey v Essex Eagles (1400)
Hove: Sussex Sharks v Hampshire (1400)