Simon Jones took the wickets of Eoin Morgan and Adam Voges with consecutive balls as Glamorgan won their rain-affected Yorkshire Bank 40 Group C match against Middlesex Panthers by 11 runs at the SWALEC Stadium.
It was the hosts’ second win in three games as they moved up to second place in the table, level on points with leaders Somerset - who they beat on Monday - and with a game in hand.
Glamorgan were asked to bat first after losing the toss and posted 153 for nine in a match reduced to 25 overs per side, but Middlesex could only make 142 for nine despite skipper Neil Dexter scoring 54 from 52 balls.
The hosts made a fortuitous start when Gareth Rees top-edged Steven Finn for six in the first over but the England bowler soon got his revenge, having Mark Wallace caught at point.
Toby Roland-Jones then struck twice to remove Chris Cooke and skipper Marcus North to reduce Glamorgan to 38 for three.
Jim Allenby's arrival saw some impetus injected into the innings as he took a four and a six off consecutive balls from Dexter.
Paul Stirling's part-time off-spin claimed two wickets as Allenby holed out on the midwicket boundary and Murray Goodwin top-edged a sweep to short fine-leg, and when Rees was bowled by James Harris Glamorgan were left on 89 for six.
The start of the batting powerplay saw Ben Wright hole out to Finn, ending a 43-run partnership with Graham Wagg, who helped Glamorgan take 21 runs from the final three overs.
Middlesex struggled at the start of their reply. Allenby bowled Dawid Malan with the fifth ball of the innings and an impressive Michael Hogan over saw Joe Denly edge behind to leave the Panthers 14 for two at the end of the fourth.
Allenby struck again in the seventh over as Stirling drove him straight to mid-off, before Jones made his decisive mark.
The former England paceman got the prized wicket of Morgan with his third delivery, helped by a well-taken catch from Chris Cooke diving forward at cover, and followed it up by trapping Voges lbw to reduce the Panthers to 32 for five.
Middlesex were briefly offered hope through John Simpson and Dexter, who put on 59 in nine overs until the impressive Simpson was snaffled at midwicket off Dean Cosker.
Dexter’s half-century meant a faint sniff for his side but their hopes of scoring 20 from the final over all but ended when he departed to its second ball.