Lancashire hung on to claim a nine-run victory over Leicestershire at Old Trafford, their fifth win from seven keeping them tied at top of the North Division.
The hosts posted 166-7 from their 20 overs despite Richard Jones taking 5-34 on his Leicestershire debut, following his loan move from Warwickshire earlier in the day.
Leicestershire stayed just about in contention until the final over, from which they needed 17 runs, but Kabir Ali kept it tight enough as the visitors ended on 157-7.
The hosts got off to a fast start with opener Tom Smith hitting 50 off 36 balls but Jones was among the wickets to make a dream start to his Leicestershire career.
Paul Horton joined forces with Smith to put on 50 for the third wicket before the latter was trapped lbw by Rob Taylor.
Leicestershire made the fast start they needed thanks to opener Josh Cobb but Jordan Clark bowled his opening partner Niall O'Brien for nine in the third over.
By the end of the six powerplay overs Leicestershire had lost Cobb and Greg Smith as well, and after 10 overs they were 74 for three.
Matthew Boyce top scored with 47 before he was bowled by Junaid Khan, and off the final ball Kabir found Taylor's stumps to seal victory in style for Lancashire.
Worcestershire also made it five wins from seven with an eight-run victory over Derbyshire at the County Ground.
Skipper Daryl Mitchell (68 not out) and Colin Munro (65) starred as Worcestershire ran up 177-5 and Derbyshire fell just short as visiting seamer Chris Russell (4-40) took three wickets off the final four balls of the match.
An unbeaten partnership of 67 from Laurie Evans and Ateeq Javid laid the foundations for Birmingham to claim an 18-run win over Nottinghamshire at Trent Bridge.
England duo Alex Hales (30) and Michael Lumb (24) looked to be powering Nottinghamshire to victory as they put on 57 in just 5.1 overs for the opening wicket, but after both fell in the same Shoaib Malik over the hosts badly lost their way as they slumped to a second loss in the North Division.
Evans earlier helped salvage a decent score for Warwickshire with an unbeaten 45 off 23 deliveries after Nottinghamshire all-rounder Samit Patel (3-26) had shone with the ball.
Defending champions Northamptonshire slipped to their second defeat after losing by 16 runs at home to Yorkshire, who scored 181-3 off the back off a rapid 60 from Jonny Bairstow.
Richard Levi threatened to take the match away from Yorkshire with a brutal 76 at the top of the order, the South African striking five sixes and five fours, but he did not get the support he needed as orthamptonshire were limited to 165-9 in reply.