Jamie Porter ripped through some fragile batting with four wickets to help skittle Somerset for 99 and put Essex on course for only their second home Rothesay County Championship victory of the season.

Ably supported by debutant seamer Charlie Bennett, and latterly spinner Simon Harmer, Porter took his season’s tally to 49 wickets with figures of 4-18 from a dozen overs. It left Essex requiring 95 to win before bad light ended play on day three 17 overs early.

At one stage, when Dean Elgar and Paul Walter were putting on 277 for the first wicket the day before, it had looked as if Essex would gain a sizeable first-innings advantage. In reality, that lead turned out to be just five runs as they lost all 10 wickets for an additional 161 runs inside 45 overs. But that was before Somerset went in for a second time.

Much of the damage in Essex’s first-innings 438 was down to some naggingly accurate bowling from Craig Overton, who passed 500 first-class career wickets while posting figures of 6-88. What had been a docile, one-paced wicket suddenly turned into a seamer’s dream and Overton capitalised with his second six-wicket haul of the season.

Essex’s seamers were also quickly among the wickets in Somerset’s second innings. Porter beat Archie Vaughan for pace and then Bennett had Tom Lammonby lbw to one that stayed low.

James Rew appeared to be repairing the initial damage, harvesting four boundaries in his run-a-ball 19, until he skied a leading edge to midwicket off Bennett. Then in the next over, Tom Kohler-Cadmore may have lost the ball in the gathering gloom as Doug Bracewell bent back his off-stump. The floodlights came on soon after.

Josh Thomas had been immune to the carnage around him, hitting seven fours in his 39 from 65 balls, but he became Porter’s 550th first-class wicket for Essex when one kept low and trapped him lbw. In the same over, Kasey Aldridge tickled one through to substitute wicketkeeper Simon Fernandes.

With Somerset disappearing down a rabbit hole at 89-6, Essex announced free admission for all spectators on the final day. Overton then made a swift exit, playing all around one from Porter. And it became worse when Jack Leach set off for a run, pushing Porter into the covers, but could not recover his ground before Charlie Allison’s throw enabled Fernandes to whip off the bails.

Lewis Goldsworthy dug in for 58 balls, but he was undone by a spectacular delivery from Simon Harmer that pitched well outside off-stump and turned square to bowl him. And Jake Ball followed to one from the spinner that went straight on and disturbed his stumps. Somerset all out inside 34 overs.

Under dirty grey clouds in the morning, things had looked brighter for Somerset when Overton claimed a second wicket in 10 balls, separated by overnight rest and recuperation. He dug in a short delivery and Tom Westley hooked obligingly to deep square leg.

Elgar lasted just another half-an-hour. He added just seven runs to his day-two total before he was lbw for 118 playing all around the second ball of an Aldridge spell.

Overton, returning for another spell with the second new-ball already four overs old, struck with his 13th delivery, slanting one in at pace and flattening Allison’s middle stump.

Lewis Gregory had looked the most lively of the Somerset attack, beating the bat on a number of occasions, and finally received some reward, Matt Critchley lbw playing down the wrong line.

On the stroke of lunch, Michael Pepper became Overton’s fifth victim when he was lbw trying to force the ball through midwicket.

Gregory lasted eight deliveries in the afternoon session before pulling up injured and briefly leaving the pitch. He, therefore, missed Overton’s sixth wicket when Bracewell looked to swing lustily to leg but ended up dollying a catch to wide mid-off.

Bennett produced some aggressive hitting with five fours in a 26-ball 22 before he gave a tame return catch to Leach. Porter smashed his first ball straight for six to take Essex into the lead but perished when he skied Leach into the covers.

The umpires have decided no play will be possible this afternoon.

Essex will need 95 to win tomorrow morning.

Bad light delays the restart; updates as we get them.

Ball is bowled by Harmer and Essex require 95 to win!

Light meters are out and we will see if the umpires allow more play.

Goldsworthy goes back to a Harmer delivery and is bowled, Somerset nine down with an injured Gregory at the non strikers end.

MIXUP!! Exactly what Somerset didn't need. Leach knocks one into the covers and sets off. Lewis Goldsworthy didnt send him back in time and he is miles out.

This game may be done today.

Porter has FOUR! Overton LBW and Somerset on the brink at 91/7.

Double wicket maiden!! Porter finds the edge of Aldridge and Somerset are in lots of trouble here at 89/6.

One keeps low on Josh Thomas, skids on and strikes him on the pad. It looked very adjacent, and he is LBW to Porter.

Kasey Aldridge joins Lewis Goldsworthy in the middle for Somerset.

Back out there after the tea break, Lewis Goldsworthy strikes the first ball for four.