Nottinghamshire missed a chance to secure a Yorkshire Bank 40 semi-final slot as they lost by 38 runs to Worcestershire at Trent Bridge.
Set a target of 221 in 37 overs after afternoon showers had delayed the start, the home side were bowled out for 182, with James Taylor remaining unbeaten on 67.
Taylor had been left with the lower order after Worcestershire had reduced Nottinghamshire to 83-5 with Moeen Ali claiming the wickets of Samit Patel, David Hussey and Riki Wessels on his way to figures of 3-28.
Daryl Mitchell had earlier top-scored with 56 as the visitors posted 220-8 after being invited to bat first.
Mitchell shared in an opening stand of 58 with Ali (28) before pairing up with Alexei Kervezee, who hit a run-a-ball 31 in a second-wicket partnership worth 49.
Tom Fell added 25 and Thilan Samaraweera, who launched the only maximum of the evening, continued the momentum before being trapped lbw by Jake Ball for 38, who ended with two for 38.
In a comical conclusion to the innings, Ross Whiteley survived three run-out attempts on his way to making just six and Brett D'Oliveira was bowled by a Harry Gurney no-ball in the penultimate over.
Ajmal Shahzad claimed figures of three for 54, conceding a flurry of late runs as the lower order tried to scramble their way to a respectable total, and Gurney collected 2-39.
Paceman Graham Cessford, on his Worcestershire one-day debut, came under an early assault from both Michael Lumb and Alex Hales, who picked him off for five boundaries in his first two overs.
But Lumb then fell to Jack Shantry before Ali blew a hole in the batting card with three quick wickets, while Charlie Morris removed Hales for 31.
Taylor passed fifty for the fifth time in this year's competition but then lost partner Chris Read, who holed out for 25.
A direct hit from point by D'Oliveira ran out Steven Mullaney, who had received his county cap prior to the start, and the same fielder then caught Shahzad to give Cessford his maiden wicket at this level.
Morris delivered the final blow as he clean-bowled Gurney with four overs left unbowled.
While Worcestershire celebrated only their fourth win of the year, Nottinghamshire were left still needing victory over either Sussex or Kent from their final two matches to reach the last four.