Craig Kieswetter's aggressive 76 and a nerveless last over from Yasir Arafat helped Somerset reach the Friends Life t20 quarter-finals for the fifth successive season.
The duo's efforts sealed a dramatic 10-run win over Warwickshire Bears in their final Midlands/Wales/West Group match, a winner-takes-all contest with both sides eyeing a spot in the last eight.
Arafat conceded only three runs in his final over, which ensured Kieswetter's 53-ball innings was not squandered.
An unbroken fourth-wicket stand of 100 between Darren Maddy and Laurie Evans was not quite enough to take Warwickshire into the knockout stages for the first time in three years.
England international Kieswetter, who became the first batsman in the country to top 400 runs in the competition this season when he reached 29, reached his fourth half-century of the summer from 43 balls and accelerated by taking 24 off what proved a costly and decisive over from Maddy.
Kieswetter received excellent support from Peter Trego and Nick Compton, who both made 32 from 23 balls.
Trego dominated a second-wicket stand of 45 with Kieswetter while Compton played a supporting role in a third-wicket partnership of 82 from 46 balls.
Kieswetter, who struck four sixes and four fours, eventually lost his middle stump when giving himself room to scoop Boyd Rankin for another boundary.
Rankin, capped by England in two Twenty20 internationals against New Zealand last month, uprooted James Hildreth's middle stump next ball yet bowled only three overs despite being the pick of Warwickshire's attack with 2-9.
That proved a costly decision by Warwickshire's acting captain Varun Chopra as Somerset piled up 175 for five, a total they expertly defended against a side who had won five of their six previous matches chasing.
Maddy did his best to atone for his costly bowling by rattling to a 37-ball half-century but was left unbeaten on 67 in his final FLt20 innings before he retires from county cricket at the end of the season.
Evans ignored the discomfort of a dislocated finger, sustained when he dropped Compton at deep midwicket, and stroked a 32-ball 50.
However, he managed only a single off the first three balls of Arafat's accurate final over as Somerset progressed.