Lancashire secured a top-two spot – and a home quarter-final – in the Vitality Blast North Group with a 25-run victory over holders Worcestershire at New Road.
Steven Croft hit a career-best equalling 94 as the visitors totalled a formidable 218 for five after being put in.
Saqib Mahmood then pressed home Lancashire's advantage by removing openers Hamish Rutherford and Riki Wessels in his first two overs.
The game was effectively ended when Worcestershire captain Moeen Ali became the first of two wickets to fall in spinner Glenn Maxwell's first over.
Ross Whiteley ended unbeaten on 89 from 40 balls as Worcestershire closed on 193 for seven.
Nottinghamshire pulled off an astonishing final-ball victory over Yorkshire at Trent Bridge to guarantee qualification for the quarter-finals.
Defending a total of 148 for seven, Nottinghamshire seemed certain to be on the wrong end of the result as the visitors coasted to 99 for two.
Harry Gurney, with two for 29, including a crucial wicket in the final over, derailed the run chase, with Luke Fletcher also taking two for 31.
Yorkshire required 12 from the final six balls but fell short on 145 for seven, leaving Nottinghamshire victors by three runs.
Faheem Ashraf saw Northamptonshire home with two balls to spare at Edgbaston as Birmingham lost by four wickets.
Northamptonshire began the day having to win their last three matches to reach the top four of the North Group and were cruising in a chase of 151 at 128 for two in the 15th over.
Wickets began to tumble and five were needed from five balls but Ashraf guided Henry Brookes wide of third man for two and struck the winning boundary over extra cover.
Derbyshire all but sealed qualification for the quarter-finals after comprehensively beating Leicestershire by nine wickets in a crucial North Group clash at the County Ground.
Captain Billy Godleman led the way with an unbeaten half-century, his third of the competition, after seeing his side dismiss Leicestershire for just 124.
Godleman finished on 52 and Wayne Madsen 37 not out as Derbyshire reached 128 for one with nine balls to spare.
Hampshire and Essex tied for the second year in a row as Adam Zampa ran half-century maker Sam Northeast out on the last ball of a thrilling South Group match.
Hampshire, chasing 140 to win, needed 11 off the final over having previously required 42 from 18 balls.
They got it down to two from the last delivery with Northeast on strike, but his shot down the ground could only find Zampa, who easily had Northeast out of his ground attempting a second. Hampshire finished on 139 for six in reply to 139 for seven.
