Defending champions Notts Outlaws and Sussex Sharks claimed the last two quarter-final places in the T20 Blast with wins over Yorkshire and Middlesex respectively.
Yorkshire's eight-wicket loss sent them out of the competition. David Willey made 51 in the Vikings' 163-6 at Headingley, but Alex Hales' 71 not out saw Notts home.
At Hove, fifties for Sussex openers Phil Salt (66) and Luke Wright (74) took them to 215-5 before they bowled Middlesex out for 184.
Worcestershire beat Birmingham Bears thanks to Moeen Ali's brilliant 115 off 56 balls and finished top of the North Group.
Kent Spitfires chased 202 to win at neighbours Essex Eagles and earn a home quarter-final, but could not overtake South Group leaders Somerset.
Surrey beat Glamorgan in a rain-affected game in Cardiff, but Sussex's victory knocked both sides out.
Quarter-final ties (all times BST)
- Thursday, 23 August - Kent v Lancashire - 19:00
- Friday, 24 August - Durham v Sussex - 18:30
- Saturday, 25 August - Worcestershire v Gloucestershire - 15:00
- Sunday, 26 August - Somerset v Notts Outlaws - 15:00
The four winners go through to Finals Day at Edgbaston on Saturday, 15 September.
Hales shows international class
Set a target of 164 on a tricky pitch, the Outlaws rarely looked in trouble with England opener Hales at the crease.
The 29-year-old only hit five fours and one six, but picked off Yorkshire's experienced attack to control the chase perfectly.
Tom Moores played the more aggressive knock, smashing an unbeaten 43 off 24 balls, and ended the game with back-to-back sixes over mid-wicket.
Earlier Yorkshire struggled to build momentum in their innings, with Willey and Adam Lyth (44) getting out when well set.
New Zealand captain Kane Williamson provided a late surge with 44 off 26 deliveries, but their total looked short against Notts' explosive batting line-up.
Sharks survive a scare
In a dramatic game on the south coast, Sussex found themselves sliding towards defeat, despite setting already-eliminated Middlesex 216 for victory.
Paul Stirling and John Simpson bludgeoned the home bowlers to all parts of a sold-out Hove to take the visitors to 123-1 in the ninth over.
However, once spinner Will Beer bowled Ireland opener Stirling for 58, Sussex managed to claw the game back.
Wicketkeeper Simpson went a couple of overs later for 62 off 29 deliveries and the rest of the card folded - thanks to some fine pace bowling from Chris Jordan (2-26) and Tymal Mills (2-31).
Friday's other matches saw Durham's game against Derbyshire rained off without a ball bowled, although the Jets had already earned a home knockout tie.
Hampshire won by six wickets at Southampton as Gloucestershire slipped to fourth in the South Group.
Northants Steelbacks finished their miserable campaign with a four-wicket victory at Leicestershire in a meeting of the North Group's bottom two at Grace Road.