Opener Toby Albert had retired damage after he had prolonged his knee when taking a fast single on the second night, however his return was short-lived as Gregory had him leg-before.
Ben Mayes was bowled by the gate by Archie Vaughan, however Somerset wrestled again the benefit with the second new ball.
Vaughan tempted Liam Dawson right into a free leg facet shot, earlier than Gregory introduced himself on, discovered good motion and 4 extra wickets.
Ben Brown was the most recent candidate to interrupt the century curse, however was stopped on 66 by an inswinger.
Kyle Abbott and Eddie Jack had been additionally bowled, earlier than Sonny Baker was lbw – Gregory coming back from a pectoral harm that had dominated him out of the opening two rounds in fashion.
This was his first five-wicket haul in opposition to Hampshire, regardless of taking extra wickets in opposition to the opponent than another in first-class matches.
In his six overs with the second new ball, throughout which he swapped ends, he took 4 wickets for 5 runs, with general figures of 5-42.
Vaughan noticed the 287 goal as one to assault, regardless of there being loads of time left within the match. The opener bought the chase in opposition to Essex performed and dusted in fast time, and struck six boundaries in a 30 earlier than taking up a Baker brief ball and shedding for the second time within the match.
Baker swapped ends and eliminated the remainder of the Somerset prime order. Josh Thomas was plumb in entrance after which Tom Lammonby hooked straight to deep sq. leg.
Not for the primary time within the match, or the season, Somerset regarded to Rew and Tom Abell to construct an necessary partnership – they as soon as once more answered with runs.
The pair placed on 87, after 101 within the first innings, with Rew doing nearly all of the run scoring.
