Somerset 128 (Porter 5-37, Cook 5-38) and 170 for 7 (Dickson 42, Snater 4-55) beat Essex 156 (Westley 43, Pretorius 4-36) and 138 (Davey 3-20, Gregory 3-23) by three wickets
Somerset's Matt Renshaw and Sean Dickson tamed a seaming pitch to lay the foundation for a three-wicket Vitality County Championship First Division win over Essex inside two days at Taunton.
When the visitors were bowled out for 138 in their second innings, 30 wickets had fallen in the match. There were three each for Somerset seamers Josh Davey and Lewis Gregory as Jordan Cox top scored with 27 on a still green wicket.
A target of 167 to win looked stiff for the home batting line-up given what had gone before. But Renshaw (35) and Dickson (42) put together an opening partnership of 75 and, although the Essex bowlers stuck gamely to their task, Somerset always looked favourites from then on.
Andy Umeed made 34 and Tom Banton's 29 off got them over the line to take 19 points, while Essex had to settle for three.
Somerset's seamers were soon among the wickets when their opponents began the day on six without loss in their second innings. Dean Elgar glanced a catch to wicketkeeper James Rew off Davey at 11 for one and, with four runs added, Sam Cook was caught at third slip by Umeed off Craig Overton, fourth slip Dickson scooping the ball up one-handed to his team-mate.
It was 37 for three when Tom Westley fell lbw pushing forward to Davey before Nick Browne and Jordan Cox added 30. Browne, on 23, then got an inside edge onto his pad to send a delivery from Gregory looping up for a catch at third slip.
It was 95 for four at lunch, with the Essex lead 123. The fifth wicket fell on 106, Matt Critchley nicking a ball from Davey through to Rew, who claimed a low diving catch in front of the slips.
Overton cranked up his pace and forced Cox to edge to second slip where Tom Lammonby pouched a routine catch. Thain and Harry Duke took the score to 137 before the last four Essex wickets fell in quick succession, Duke feathering a defensive shot off Jake Ball through to Rew and Thain pinned lbw by Gregory.
Simon Harmer was trapped leg before by Ball and when Rew produced another low diving catch to send last man Jamie Porter back for a duck it meant a third wicket for Gregory.
Soon openers Renshaw and Dickson set about the target of 167 in positive fashion against Cook and Porter with the sun shining brightly. Both went for their shots and by tea they had taken the score to 45 without loss off 11 overs, leaving Somerset needing just 122 more runs for victory.
Dickson took the stand past 50 with a glorious off-drive for four off Shane Snater and followed up with a six over long-on in the same over. Renshaw joined in with a flashing square drive for four off Cook.
When Renshaw edged Snater the ball fell agonisingly short of the slip cordon. Cook gave Essex hope by dismissing Renshaw lbw with the total on 75, but by then only 92 were required.
Dickson followed in the next over, caught behind the ball after hitting his third four and suddenly Somerset had two new batsmen at the crease. But Umeed carried on applying pressure to the Essex bowlers, hitting two straight fours in an over from Cook.
Lammonby matched his first innings patience, but having faced 23 balls without scoring he padded up to a delivery from Snater which nipped in off the seam and fell lbw with 68 still needed.
Umeed had faced 55 balls, hitting 5 fours, when edging a ball from Snater, which cannoned off wicketkeeper Duke and looped to Harmer at second slip. With 47 required, Somerset needed to keep their heads.
Migael Pretorius failed in that respect, lofting a catch to extra cover off Cook and Rew was spilled on one at third slip by the diving Critchley. He fell before the close, but Banton's largely sensible knock had almost seen his side home when he edged a slip catch off Snater.
It was left to Overton to hit the winning boundary off Porter in the second additional over of the day to give Somerset their first win of the season after four draws.