Reigning champions Hampshire beat rock-bottom Middlesex by five runs to continue their Vitality Blast title defence.
John Turner claimed three for 30 as the Hawks defended their total of 164 for six.
Ben McDermott top scored with 47 with Toby Albert scoring 32, with Middlesex unable to chase the total down.
Max Holden’s 53 from 31 balls gave Middlesex hope but Hampshire held out as the hosts remain winless, reaching 159 for seven.
Durham beat Northamptonshire by four wickets after Nathan Sowter’s heroics with the ball.
Northamptonshire hit 161 for seven, with Emilio Gay top-scoring with 53, but Sowter took four for 14 to restrict them.
Graham Clark (55) and Ashton Turner’s 31 not out helped steer Durham to victory with seven balls left.
Yorkshire cruised past Leicestershire for a 30-run win.
Yorkshire’s 156 for seven was anchored by all-rounder David Wiese’s unbeaten 50 which proved crucial.
Wiaan Mulder top-scored with 46 for Leicestershire – who were all out for 126 – but they were left needing an unrealistic 32 off the final over, with Jordan Thompson’s five for 21 helping Yorkshire to a comfortable victory.
Michael Pepper’s 48 helped Essex to a five-wicket win over Sussex.
The visitors won with 31 balls to spare after easily reaching 149 for five to win, thanks also to Adam Rossington’s 35 and Daniel Sams’ unbeaten 29.
Sussex were bowled out for 147, spearheaded by Ravi Bopara’s 50, but Sam Cook’s four for 20 was key for Essex.