Worcestershire left Somerset's hopes of reaching the quarter-finals of the Friends Life t20 hanging by a thread after an Andre Russell-inspired five-wicket victory at New Road on Saturday.
West Indies all-rounder Russell proved his worth as the club's overseas recruit with a breathtaking innings of 77 not out from just 42 balls to help Worcestershire chase down 188-4 in the final over.
Russell shared an 88-run partnership with Worcestershire debutant Ross Whiteley (43 off 30) before hitting the winning runs with two balls to spare.
Worcestershire moved off the bottom of the Midlands/Wales/West Division with the win, however Somerset must beat Warwickshire in their final group match on Monday to be guaranteed of a place in the knockout stages.
Somerset looked all-but assured of a place in the last eight at the halfway stage of the match after Craig Kieswetter (80 off 56) and Peter Trego (62 from 31) had both cracked half-centuries to propel the visitors up to 188-4.
Moeen Ali and Jack Leach then departed early in the run-chase and it was only when Russell arrived at the crease with the Royals floundering on 53-3 that the momentum of the match shifted.
The powerful West Indian struck five sixes to reach his 50 off only 27 balls, finding an able ally in former Derbyshire all-rounder Whiteley.
The pair took the Royals to within 18 runs of victory and Russell kept his cool when Whiteley fell for 43 to finish the job with a boundary off Craig Meschede in the final over.