Leicestershire's hopes of reaching the semi-finals of the Yorkshire Bank 40 took a blow as they crashed to a 34-run defeat against Glamorgan at Grace Road.
Chasing a victory target of 266, Leicestershire lost their way after Josh Cobb and Niall O'Brien gave them a solid start with an opening stand of 60 in nine overs.
Four wickets fell for 11 runs in seven overs and, despite a knock of 71 from Australian Joe Burns, the home side were bowled out for 231 with one ball of their innings remaining.
The win was Glamorgan's fourth of the season, and it saw them leapfrog Leicestershire into third place in the Group C table. Leicestershire, who won their first three games, have now lost three of the last four.
Put into bat, Glamorgan made the perfect start with Will Bragg taking 17 runs off Nathan Buck's first over, including a six with a free hit following a no-ball. Mark Wallace was also in good form reaching 50 off 42 balls with seven fours.
Leicestershire finally made a breakthrough when Bragg, going for another big hit off Jigar Naik, was caught at long on for 33. Wallace continued to impress but was superbly caught at cover by Ned Eckersley off Naik for 61 off 54 balls.
Chris Cooke kept the Glamorgan innings on track with 55 off 57 balls as the Foxes threatened to hit back. Left arm seamer Rob Taylor snapped up the wickets of Marcus North for 11, Murray Goodwin (41) and Dean Cosker (four) to finish with 3-57.
Buck, after his nightmare first over, removed Cooke and claimed two for 63 while Naik's two wickets cost him 39 runs.
The victory target looked well in the Foxes reach, but when Cobb was bowled by Jim Allenby for 35 they collapsed dramatically.
Greg Smith was lbw to Allenby's next delivery and O'Brien caught behind off Mike Hogan. It meant the Foxes had lost three wickets in six balls without scoring a run and it became four wickets for 11 runs when Shiv Thakor was run out.
But Burns with 71 off 77 balls with two sixes and seven fours, kept the Foxes hopes alive until driving a catch to cover off Graham Wagg. Michael Thornely (24) and Rob Taylor (22) hit some quick runs but in the end the home side fell well short. Hogan claimed 3-38 and Allenby 2-36.