Anthony Ireland's inspired spell left Derbyshire Falcons' quarter-final hopes hanging by a thread as Leicestershire Foxes eased to a 79-run victory in the Friends Life t20 North Group game at Derby.
Ireland took 4-11 in four overs that contained 14 dot balls as Derbyshire were dismissed for 79 - their lowest T20 total - chasing Leicestershire's 151 for six.
Derbyshire never recovered from Ireland's burst, Josh Cobb taking 3-19 and Shakib Al Hasan 2-7 as the innings folded in abject fashion - no doubt sparking much joy for rivals Lancashire Lightning, who qualified for the last eight as a result.
Leicestershire came into the game with no chance of reaching the quarter-finals but set a decent target after Cobb won the toss on a glorious summer's evening.
At one stage, the Foxes looked like making a more challenging total with Cobb and Greg Smith, who hit 42 off 30 balls, establishing a solid platform in an opening stand of 48.
Cobb drove Tim Groenewald for six before pulling Peter Burgoyne's off-spin to long-on and, although the Foxes reached the halfway point on 82 for one, they were unable to break free against some disciplined bowling and hit only four fours in the last 10 overs.
Smith cut Alex Hughes to backward point and Shakib fell to an ugly swipe at Dan Redfern for only three. When Ned Eckersley then drilled Hughes to long-off, Leicestershire were 125 for four in the 17th over.
Niall O'Brien's attempts to improvise failed to come off and, despite some fumbles in the field, Derbyshire restricted the visitors to 41 from the last six overs.
Wes Durston pulled Robbie Williams over deep midwicket for six in an opening over which cost 14 yet that was as good as it got for Derbyshire as Ireland destroyed the top order with four wickets for three runs in 11 balls.
Chesney Hughes lobbed a pull to mid-on, Durston was bowled for eight and skipper Wayne Madsen defeated by some late movement to be caught behind.
When Redfern edged a pull to the wicketkeeper, Derbyshire had lost four wickets in 17 balls and things only got worse as Richard Johnson was bowled by Rob Taylor.
Their hopes of pulling the game out of the fire rested on Shivnarine Chanderpaul but, after reverse-sweeping Cobb for the first boundary in 28 balls, he drove to long-off, where Ireland took a good running catch.
The last three wickets quickly followed and Derbyshire now need to beat Durham Dynamos convincingly on Sunday to have even an outside chance of advancing as the best third-placed team.