Jamie Overton led the way with three wickets as Somerset established a first innings lead of 133 on the second day of the Specsavers County Championship match with Essex at Taunton.

The 24-year-old pace bowler confirmed the return to form and fitness he showed in the Vitality Blast group matches by taking three for 40 from 8.4 overs to help bowl out the visitors for 191 in reply to 324.

There were two wickets each for seamer Josh Davey and left-arm spinner Jack Leach, with only Essex skipper Ryan ten Doeschate (73) showing much resistance.

By the close, Somerset had extended their advantage to 165 by posting 32 for one in their second innings. They look well set to press for their fifth Championship win of the season.

The day began with the hosts 308 for seven in their first innings and soon featured a milestone for Australian seamer Peter Siddle. After dismissing Lewis Gregory, who played a ball onto his stumps having made 47, Siddle claimed his 500th first class wicket when knocking back Jack Leach’s middle stump and finished with five for 80.

Jamie Porter had last man Davey caught at slip and Somerset had added only 16 to their overnight score. But that was as good as it got for Essex, who soon plunged into trouble.

An opening stand of 25 ended when Nick Browne, on 13, edged a catch behind off Davey. Soon it was 29 for three as Gregory pinned Varun Chopra lbw moving across his stumps for 16 and Tom Westley shouldered arms to a Davey inswinger, which uprooted his off stump.

Ravi Bopara (15) was well caught by diving wicketkeeper Steve Davies to give Overton his first wicket, and a half-century stand between Dan Lawrence and ten Doeschate ended with the total on 106 as Lawrence, who made 28, fell lbw pushing forward to Leach.

Adam Wheater perished for 10, edging Leach to Gregory at slip. And when Simon Harmer was caught and bowled off a leading edge by off-spinner Dom Bess, Essex were 137 for seven, still 38 runs short of avoiding the follow-on.

Essex skipper ten Doeschate moved to his half-century in the final session off 108 balls, while Siddle (12) helped add 37 for the eighth wicket. Overton finally got through ten Doeschate’s defences to trap him in front, and also dismissed Porter.