Henry Crocombe claimed his second hat-trick in eight days, and third five-wicket haul of the season, to leave Essex's batting in total disarray on an incredible evening of tumbling wickets at Chelmsford. The 24-year-old seamer, who leaves Sussex for Surrey at the end of the season, had never taken three wickets in successive balls before running through Somerset's tail at Hove last week. For an encore he helped reduce Essex from 171-3 to 177 all out in the space of 26 balls, his five wickets coming in 14 deliveries without conceding a run. He finished with 5-39.

Essex had been progressing serenely after tea on the second day of the County Championship match when Charlie Allison became Crocombe's first victim after a tidy 56. That wicket exposed the tender underbelly of Essex's batting and revived fears of a battle against relegation in the run-in to the Division One season. The collapse gave Sussex an unexpected first-innings lead of 98 after they had taken their score to 275 in the morning, thanks largely to the re-engaged Ari Karvelas thrashing six fours in a breezy 38 from 44 balls.

However, they lost Tom Haines, Tom Clark, Charlie Tear and Oli Carter second time round in extending their advantage to 188 as 11 wickets fell after tea. Karvelas was not finished when he was last man out in Sussex's first innings and, taking the new-ball, separated the Essex opening pair with an angled delivery into Paul Walter's stumps. Tom Westley then had a rush of blood and, in attempting to heave Jack Carson over midwicket, was also bowled.

With the sun breaking through and a drying wind, the wicket flattened out and batting seemed to be becoming easier than on day one. At that stage there was no hint of what was to come. Indeed, Essex reached three figures for two wickets down in 32 overs, 12 quicker than Sussex, the milestone reached with a reverse sweep for four by Allison off Carson. Allison contributed 38 of a 58-run stand with Dean Elgar before James Coles found extravagant turn with his third ball to bowl Elgar.