Moeen Ali finished with career-best figures of 12-96 as Worcestershire bowled out Lancashire for 63 to win by 205 runs with a day to spare at Old Trafford.
Set 269 for victory, defending champions Lancashire lasted 31.1 overs with spinner Ali claiming 6-29, including four caught behinds, to go with a first-innings haul of 6-67.
Gareth Cross, with 20, was the only home batsman to reach double figures. Veteran seamer Alan Richardson (2-7) and left-arm spinner Shaaiq Choudhry (2-16) supported Ali with two wickets apiece.
Worcestershire picked up 21 points for their efforts to move out of the drop zone and into sixth place in the Division One table, while Lancashire slip down a place to seventh.
Earlier on a day in which 20 wickets fell, Worcestershire had gone from 9-0 in their second innings to 139 all out.
Lancashire all-rounder Steven Croft picked up career-best figures of 6-41, including top scorer Vikram Solanki, lbw for 50.
The only good news for Lancashire was that they escaped punishment after the ECB pitch panel found that the Old Trafford pitch did not warrant a points penalty.
Lancashire were bowled out for 162 as Worcestershire dominated day two of their LV= County Championship Division One match at Old Trafford.
Off-spinner Moeen Ali took 6-67 and slow left-armer Shaaiq Choudhry claimed 4-38 as Glen Chapple's side conceded a first-innings lead of 129.
Most of the damage was done in a 25-over spell either side of lunch in which Lancashire collapsed from 65-1 to 119-9.
Stephen Moore irresponsibly holed out to Choudhry at deep mid-on off Moeen for 26 and the slow left-armer then had Paul Horton lbw on the front foot for 34.
Ashwell Prince was well beaten by Moeen's turn and edged to Ben Scott for one, and then when Karl Brown was stumped for nine attempting an ungainly heave off Choudhry to leave the home side on 86-4.
Steven Croft was bowled after being beaten by Choudhry's turn, and Tom Smith's sweep off Moeen only found the safe hands of Richard Jones at backward square-leg.
Gareth Cross, Chapple and Ajmal Shahzad were all caught at short leg by Matt Pardoe in the space of eight deliveries from Moeen as he and Choudhry, who had taken only six Championship wickets between them before this match, turned the screw on the Lancashire tail.
Kerrigan and Hogg played a little straighter than some of their colleagues and last man Kerrigan hit a six off Moeen in his innings of 20, which was his second-highest first-class score.
He was bowled attempting to hit Choudhry over the top, leaving the Worcestershire spinners with combined figures of 10-105 on a day which had thrown Ben Scott's first day century into ever sharper focus.
Ben Scott's century led a lower-order recovery as Worcestershire battled back with the bat on day one against Lancashire at Old Trafford.
The Pears looked in a serious pickle when they slipped to 93-6, Steven Croft celebrating being named in England's provisional 30-man squad for the World Twenty20 with three wickets.
In-form opener Phil Hughes was one of the all-rounder's victims, trapped lbw for 32, and when James Cameron and Gareth Andrew fell in successive deliveries to Steve Kerrigan, Worcestershire were reeling.
However, Scott combined with Matt Pardoe, who made 55 before being run out, in a resourceful seventh-wicket stand of 127 runs in 41 overs.
The wicketkeeper-batsman had made just 45 runs in 11 LV= County Championship innings prior to this match, hit 11 fours from 163 balls in his knock of 106.
Spinner Kerrigan finished with figures of 4-117 on a turning track, with Lancashire's reply reaching 13 without loss by the close of play.