Derbyshire 146 for 8 (Madsen 55) beat Worcestershire 98 (Tahir 4-17) by 48 runs
Wayne Madsen and Imran Tahir inspired Derbyshire to victory as the Falcons crushed the Worcestershire Rapids by 48 runs at Derby to secure a place in the NatWest T20 Blast quarter-finals for only the second time.
Madsen scored 55 from 42 balls, his fourth 50 of the season, to take the Falcons to 146 for 8 and then took a wicket with his second ball as the Rapids slumped to 39 for 5.
Hardus Viljoen struck twice in five balls to take 2 for 20 and with Tahir claiming 4 for 17 the Falcons sealed a place in the last eight for the first time since 2005 as the Rapids were routed for 98 with 26 balls to spare.
Madsen, thrilled at finally reaching a quarter-final, said: "I actually thought we were 20 or 25 short and we knew we had to bowl really well and that's exactly what we did . I've been waiting nine years for this. It means the world and hopefully it's just the start and we've got a few more big games to come."
The Falcons had started badly, losing Billy Godleman and Luis Reece in the first fours overs and after Matt Critchley drove Mitchell Santner for six, he miscued a pull to mid on.
At 31 for 3, a lot rested on Madsen and he responded by driving Pat Brown for three consecutive fours and pulling Joe Leach for another in the Rapids skipper's first over which cost 13.
Callum Broderick was caught at backward point reverse sweeping Santner and when Alex Hughes dragged a long hop from Brett D'Oliveira to deep square leg, the Falcons were 78 for 5.
The Rapids were bowling tightly and Madsen and Daryn Smit had to rely on placement to keep the board ticking over until Smit was stumped coming down the pitch to D'Oliveira in the 16th over.
The big over the Falcons needed came in the 18th when Matt Henry and Madsen pulled Alex Hepburn for sixes but two run-outs in the last over kept them to under 150.
Madsen was the first Derbyshire player to pass 500 runs in a T20 season and he struck an early blow with the second ball of the Rapids reply when Leach was bowled trying to cut.
Joe Clarke took two fours off Madsen and then pulled Ben Cotton's first two balls for boundaries but when he went for another big shot, he only skied a catch to point.
Viljoen landed two big blows in the sixth over when he beat D'Oliveira for pace and then pinned Ben Cox lbw with his fifth delivery and the Rapids were in deep trouble when Santner chopped on Tahir's first ball.
The visitors never recovered from losing three wickets in seven balls and a fifth consecutive defeat was inevitable when former Derbyshire batsman Ross Whiteley found the hands of Madsen at long on.