Notts Outlaws and Lancashire continue to set the pace in the T20 Blast North Group after comfortable wins over Leicestershire and Derbyshire.
Lancashire topped the group for a few hours after a crushing eight-wicket win over Derbyshire, who made only 98-7.
But the Outlaws leapfrogged them on net run-rate after chasing down 124 with five overs to spare against the Foxes.
Yorkshire beat Durham by 29 runs, and there were wins in Central Group for Gloucestershire and Birmingham Bears.
Notts had Pakistan spinner Imad Wasim back in their side for the game at Grace Road and he took 2-24 after bowling the first over of the game as Leicestershire were restricted to 123-8.
The bowlers were backed up by some fine fielding, although Chris Nash made hard work of a skied top edge by Arron Lilley (22) which he juggled before finally diving to take the catch one-handed.
Nash lasted only three balls at the start of the Outlaws reply, but Alex Hales was in punishing mood as he and Joe Clarke put on 62 in 5.3 overs before being caught after miscuing a long hop from Gareth Delany.
Skipper Dan Christian, though, made an unbeaten 33 off 26 balls and saw them home by five wickets on 124-5 with a single off Delany after striking the previous ball for six.
Derbyshire have not won a match yet and never looked likely to after struggling to 34-4 at the halfway point of their innings against Lancashire Lightning at Aigburth earlier in the day.
Alex Hughes made 32 but their total was no threat to the 2015 winners, who have one of the best opening pairs in the competition in Jennings and Alex Davies.
They added a stand of 61 to 170 and 63 in previous games before Davies was bowled for 36 by leg-spinner Matt Critchley.
A half-century was there for the taking for Jennings but he was left one run short when Dane Vilas ended the game with a glorious straight six off Leus du Plooy as Lancashire reached 102-2.
Wait goes on for Durham
Durham did not win any of their first four red-ball games in the Bob Willis Trophy and now have a record of four defeats and one no-result in the T20 Blast after losing to Yorkshire by 29 runs at the Riverside.
England Test skipper Joe Root put on 62 with Tom Kohler-Cadmore before falling for 25, caught off Paul Coughlin (2-37), as the Vikings totalled 198-3.
Kohler-Cadmore cleared the rope five times in his 85 not out off 57 balls and Will Fraine raced to an unbeaten 36 off 15 as they added 65 in five overs at the end of the innings.
Durham were in with a chance while Graham Clark was at the crease, and he took only 26 balls to bring up his fifty.
But he was stumped for 68 off Root (2-29) and the innings fell away from 152-5, with David Willey taking 3-26 as they were all out for 169 in the final over.
Yorkshire’s second win lifted them to third in the group, two points behind Notts and Lancashire.
Looking bleak for Worcestershire
Worcestershire’s hopes of repeating their Finals Day triumph two years ago are fading fast following another failed attempt to register their first win in this year’s competition.
They remain bottom of Central Group after falling well short in their attempt to chase down Gloucestershire’s total of 181-4.
Opener Chris Dent hammered two sixes and 11 fours in his career-best 87 off 52 balls and James Bracey weighed in with an unbeaten 39 off 20 at the end of the innings.
Matt Taylor nipped out both Rapids openers and their run-chase was undermined by the downfall of Brett D’Oliveira (26) and Jake Libby (33) in successive overs after a stand of 57 as they came up short on 151-9.
Gloucestershire remain second, two points behind leaders Northants Steelbacks.
Rain interrupted play at Taunton with Birmingham Bears 85-4 after 11 overs, and with the game reduced to 12 overs a side, they managed to add 22 after the restart, with Sam Hain hitting the last ball of the innings for six to reach 55 not out and take them to 107-4.
Somerset’s revised target under the DLS method was 125, but Babar Azam went for six in the opening over, caught behind off Tim Bresnan – and when the former England all-rounder’s throw from square leg ran out James Hildreth for 25 to reduce them to 36-4, the Bears were in control.
Hildreth appeared to suffer a leg injury as he tried in vain to make his ground before Jeetan Patel removed the bails at the bowler’s end.
Tom Lammonby and Roelof van der Merwe (25) put on 50 in 4.3 overs, but the task of scoring 23 from the final six deliveries proved just beyond them despite two sixes by Lammonby (43 not out off 20 balls) as they finished on 120-7 to lose by four runs.
Saturday’s fixtures (all times BST)
13:05 – Essex Eagles v Kent Spitfires – Kia Oval
18:35 – Surrey v Middlesex – Kia Oval