Worcestershire Rapids remain in third spot in the Vitality Blast North Group despite going down by 20 runs to Derbyshire Falcons at the Pattonair County Ground.
Derbyshire made 181-2 in their 20 overs with openers Billy Godleman and Luis Reece both hitting half centuries to lay the platform.
The Rapids, despite promising knocks from Martin Guptill and Callum Ferguson, were restricted to 161-7 in reply.
They are level on 10 points from nine games with Notts Outlaws, who have a superior run rate, but only two points separate six teams in the battle to reach the quarter-finals.
Worcestershire Club Captain Joe Leach made his first appearance of the season in the Blast and replaced the injured George Rhodes.
Godleman and Reece brought up their half centuries off 29 and 38 balls respectively.
Daryl Mitchell was the most economical of the Rapids bowlers in two, two-over spells and he made the first breakthrough in his final over.
Reece took one step forward and holed out to skipper Callum Ferguson at cover for 52 with the total 135 in the 16th over.
Mitchell finished with the excellent figures of 4-0-23-1.
Godleman moved onto 91 off 65 deliveries with one six and 10 fours before he fell to the first ball of the final over from Pat Brown – his tenth wicket of the campaign.
He backed away to the leg side but only succeeded in slicing the ball onto the off-side and into the hands of Ross Whiteley in the deep.
Brown ended with 1-35 from his four overs.
When the Rapids began their reply, Guptill helped a delivery from Ravi Rampaul on its way over the third man boundary for six.
But fellow opener Riki Wessels was run out in the second over – from Ravi Rampaul – after a mix-up with Guptill.
Guptill played the West Indian towards mid on and set off for a single but Wessels (1) only ventured a few yards out of his crease at the non striker’s end.
Rampaul was flicked off his legs for four by Guptill while Ferguson cut Fynn Hudson-Prentice for four and drove the same bowler to the boundary.
The Rapids reached 45-1 by the end of the six over powerplay.
Ferguson powered Boyd Rankin high over mid-wicket for six and pulled the next ball for four before Guptill drove Reece for six over long on to leave the Rapids needing 100 from the last 10 overs.
But the introduction of spinner Matt Critchley on his 23rd birthday proved a big turning point in the outcome of the game.
Ferguson – having made 37 off 26 balls – drove Critichley to long on and Guptill – 45 off 40 deliveries – was bowled trying to cut the same player.
Wayne Parnell, after driving Critchley for six, failed to clear long off when he tried to repeat the shot and was dismissed for seven.
After Ross Whiteley (10) had lobbed a Luis Reece delivery up in the air on the off side, Ben Cox (15) became Critchley’s fourth victim.
Ed Barnard finished unbeaten on 29 from just 17 balls but the Rapids fell short with Daryl Mitchell (6) out to the last ball of the innings from Rampaul.