Peter Trego claimed 4-22 as Somerset completed a remarkable turnaround to beat Worcestershire by an innings and eight runs at New Road.
The Pears had piled up 488 on the first day-and-a-half of the contest but still found themselves conceding a first-innings deficit of 103 as Somerset, led by skipper Marcus Trescothick's double century, responded with 591-9 declared.
Worcestershire began to final day on 4-0 in their second innings and promptly collapsed to 95 all out by early afternoon.
Seamers Trego and Alfonso Thomas (3-13) did most of the damage on a wearing pitch as Worcestershire captain Daryl Mitchell top scored with 26 in an innings that lasted only 39 overs.
Steve Kirby (1-16) angled his second delivery across Matt Pardoe to have the opener caught at first slip and Vikram Solanki edged Trego's fifth ball to second slip.
Moeen Ali, having made a career-best 158 in the first innings, got to 10 before a top-edged pull gave Thomas an early success and worse still for Worcestershire, this led to a clutch of wickets.
Jack Manuel was bowled by spinner Murali Kartik (2-25) from only the third ball he faced and Thomas accounted for Gareth Andrew and Alexei Kervezee, the latter giving James Hildreth his fifth catch of the match.
Mitchell stayed for nearly two hours but Trego ended his resistance with the second ball of a new spell, which shot through low. Trego and Kartik then mopped up the last three wickets for 11 runs in six overs after lunch, leaving Ben Scott unbeaten on 15.
Back-to-back wins have now lifted fourth-placed Somerset to within 23 points of LV County Championship Division One leaders Durham.
Marcus Trescothick's fifth career double hundred enabled Somerset to take a stranglehold on their LV= County Championship clash with Worcestershire at New Road.
The visitors were, to say the least, in the runs on Thursday, with Trescothick making 203 in nearly six-and-a-half hours and four other half-centuries coming Somerset's way.
Resuming on 106 not out, Trescothick's opening stand of 207 with Arul Suppiah (88) set the stage and he also added 151 with Nick Compton (95) before finally departing mid-afternoon to a catch at mid-off by Alexei Kervezee.
Compton went on to share a stand of 97 with James Hilldreth (67) as he reached 1,000 runs in a season for the second time, while Craig Kieswetter (68 from 73 balls) rammed home Somerset's advantage.
They eventually declared on 591-9 - a lead of 103 and their highest-ever score against Worcestershire.
The home side initially pinned their hopes on Saeed Ajmal getting the ball to turn and, although a profitable final spell gave him figures of 5-150 in 51 overs, it was mostly a day of toil.
The one tiny flaw for Somerset was that they missed a fifth batting bonus point by 28 runs but they go into the final day sniffing a chance of victory with the home side on 4-0 after two overs.
Marcus Trescothick's sixth LV County Championship century of the season ensured Somerset made a strong start in reply to Worcestershire's 488 at New Road.
Trescothick and opening partner Arul Suppiah batted throughout the final 60 overs of day two to leave the Cidermen at 198-0 in their first innings, still 290 behind.
The Somerset captain found the boundary 18 times to reach the close unbeaten on 106 from 166 deliveries, taking his season's tally to 1,504 in 20 innings - more than 400 ahead of his nearest rivals.
Suppiah played an excellent supporting hand with 86 not out from 194 balls, including 14 fours, while Worcestershire spinner Saeed Ajmal had figures of 0-47 in 18 overs on a dry pitch.
The Pears had earlier advanced their first innings from 367-3 to 480 all out.
Moeen Ali, on 134 overnight, reached a career-best 158 before being one of four victims in the morning session for Charl Willoughby (4-115).
Moeen Ali's sixth first-class century powered Worcestershire to 363-7 by stumps on day one against Somerset at New Road.
Ali finished unbeaten on 134 and shared three-figure stands with Vikram Solanki (90) and Alexei Kervezee (68no).
The Pears opted to bat first after winning the toss and lost Matt Pardoe (9) in the fourth over, caught by Marcus Trescothick at second slip off paceman Steve Kirby's bowling (1-66).
Skipper Daryl Mitchell and Solanki put on 73 before seamer Peter Trego (1-54) removed Mitchell for 45 just prior to lunch.
But Somerset failed to take a wicket during the afternoon session as Ali dominated a 148-run, third-wicket stand with Solanki.
Spinner Murali Kartik (1-74) denied Solanki a century but Ali went to three figures for the first time in 10 months from 151 balls, bringing up the landmark with a top-edged six off Trego.
At the close he had also hit 18 fours and added an unbroken 128 for the fourth wicket with the ever-positive Kervezee, who hit nine boundaries in a 61-ball half-century.