Middlesex will meet Kent in the Twenty20 Cup final after thrashing Durham by eight wickets in the second semi-final at the Rose Bowl.
Set a target of 128, Tyron Henderson smashed seven sixes during an innings of 59 off 21 balls to see Middlesex home with 4.2 overs to spare.
The South African-born all-rounder shared an unbroken third-wicket partnership of 76 from 36 deliveries with Owais Shah, whose contribution was a relatively sedate 13.
Durham's much-vaunted seam attack, particularly Steve Harmison (0-47), went round the park as skipper Dale Benkenstein tried in vain to stem the flow of runs.
Harmison, who found out on Saturday morning that he has been recalled by England for next week's third Test against South Africa, topped 90mph regularly but found his additional pace was very much to Henderson's liking.
Middlesex openers Billy Godleman and Ed Joyce had set the platform with a stand of 65.
Both fell to spin in quick succession - Godleman (20) trapped lbw by Gareth Breese (1-14) and Joyce (41) stumped off Paul Wiseman (1-31) - but that just hastened the game's conclusion by bringing the big-hitting Henderson to the crease.
Durham posted a below-par total of 138-6 after opting to bat first.
Paul Collingwood threatened to cut loose during a knock of 35 from 31 balls but departed to Shaun Udal (1-18) as the squeeze was applied by Middlesex's spinners during the middle overs.
Shivnarine Chanderpaul top-scored with 48, however the Guyanan left-hander laboured for 47 balls for those runs and in-form Will Smith (21) also struggled to find the boundary with the regularity required in this format.
Tim Murtagh, who removed Michael di Venuto (0) and Phil Mustard (15) during his opening spell, returned later to account for Chanderpaul and finish with figures of 3-29.
The result eliminated the potential for fall-out from the England and Wales Cricket Board's decision to prevent Middlesex batsman Andrew Strauss playing in finals day.
Strauss' enforced rest on one of the biggest days of the domestic summer was in stark contrast to Durham, who had both of their centrally-contracted players - Collingwood and Harmison - available.