Essex proved themselves as serious Specsavers County Championship title contenders as they condemned Division One table-toppers Somerset to their first defeat of the season.

Fast bowler Jamie Porter followed up his five for 51 in the first innings by blasting through Somerset’s batting line-up with figures of four for 22 – as the early pacesetters were bowled out for 117 to lose by 151 runs at Chelmsford.

Somerset were set 269 runs to win, having briskly taken the last four Essex wickets, but were bowled out inside 33 overs – Porter and Simon Harmer sharing three wickets in 17 balls after lunch.

Surrey face an anxious final day against Warwickshire at the Kia Oval as their former batsman Dominic Sibley leads a determined attempt to chase down 290 for victory.

At stumps on day three Sibley was unbeaten on 52 as Warwickshire reached 148 for three in their second innings, although they lost Sam Hain for 26 when he was stumped off Gareth Batty three overs before the close.

Some impressive seam bowling saw Gloucestershire grab a narrow advantage on the third day of their Division Two match with Glamorgan at Bristol.

David Payne, Josh Shaw and Ryan Higgins ended with three wickets each as the visitors were bowled out for 287 from an overnight 187 for four – a first-innings deficit of 26.

Marnus Labuschagne contributed 65 and Graham Wagg 33, but it was a struggle for the Glamorgan batsmen with the floodlights on beneath heavily overcast skies.

By the close, Gloucestershire had made 41 for two in their second innings and led by 67, with James Bracey unbeaten on 14.

Durham outplayed promotion hopefuls Sussex until tea at Hove before the home side counter-attacked thrillingly in the final session.

Resuming on 259 for five on the second morning, Durham went on to make 384 and then reduced Sussex to 96 for five at tea before David Wiese and Delroy Rawlins cheered up local supporters with some spirited strokeplay in the long shadows.

The second day of Leicestershire’s fixture at Northamptonshire was completely washed out, with the visitors hoping to resume on six without loss on Wednesday, 293 runs behind.