Somerset 199 and 269 for 5 (Abell 62, Hildreth 58) beat Yorkshire 103 (van der Merwe 3-14, Davey 3-30) and 127 (Davey 5-21) by 298 runs
Somerset's hopes of a first ever County Championship title were given a massive boost by a crushing 298-run victory over Yorkshire inside three days at the Cooper Associates County Ground, Taunton.
Set an unlikely 426 to win, the visitors were bowled out for just 127, with Will Fraine forced to bat at seven with a runner because of a knee problem and Ben Coad absent ill. Seamer Josh Davey claimed five for 21 from 11.2 overs.
Somerset had earlier built on their overnight second innings score of 269 for five before being dismissed for 329, George Bartlett making 47, Roelof van der Merwe 30 and Jamie Overton 18, including 2 two towering sixes.
Keshav Maharaj returned five for 122 for match figures of 10 for 176 to become Yorkshire's leading Championship wicket-taker this season with 38 in only five appearances.
Somerset took 19 points from the game to Yorkshire's three and, with Essex battling to save their Championship game against Warwickshire, the Cider county look set to enter the last two games in pole position to win the competition.
The day began with Somerset looking to add quick runs. They lost Lewis Gregory (39), Bartlett and Dom Bess early on, but van der Merwe and Overton produced some lusty blows to take the lead beyond 400.
There was a moment of humour when van der Merwe pulled a ball towards the boundary, ran while following the path of the ball, and crashed into bowler Tim Bresnan in mid-pitch. Both sturdily-built men went down, but with no injury resulting from an incident inevitably bound for Twitter.
When van der Merwe fell to Maharaj, it meant the left-arm spinner had taken 31 wickets in six innings against Somerset. But the home side were buoyant over what looked sure to be a winning lead and soon set about finishing the match.
Adam Lyth was well caught low down at third slip by Jamie Overton off Davey with only seven on the board and Gary Balance fell in the final over before lunch, caught behind off a snorter from Overton.
Jonathan Tattersall had replaced Fraine as Lyth's opening partner and he was unbeaten on 14 at the interval, with Yorkshire 47 for two.
That became 54 for three when Tattersall, on 20, was caught at first slip by James Hildreth looking to withdraw the bat from a delivery by Overton, who was working up good pace from the Somerset Pavilion End.
Harry Brook fell to a poor shot, bowled playing back to van der Merwe and it was 94 for five when Bresnan, who had pulled a defiant six off Gregory, was run out by a direct hit from Bess at backward point after a mix-up with Tom Kohler-Cadmore over a single.
Kohler-Cadmore edged another catch to Hildreth off the impressive Davey, who quickly followed up by pinning Maharaj leg-before for a duck and taking a return catch to remove the stricken Fraine.
Steve Patterson delayed the inevitable with a fighting 24 not out, but when Duanne Olivier was well caught by Bess over his shoulder at point off Davey the Yorkshire innings ended as Coad was unable to bat.
Davey, playing only his fourth Championship match of the season, returned match figures of eight for 51. It was Yorkshire's fifth heaviest first class defeat in terms of runs.
Somerset travel to the Ageas Bowl to face Hampshire next week before a potentially historic home game against Essex, starting on Monday September 23.