Essex 245 and 85 for 1 (Westley 51*) lead Derbyshire 266 (Masters 5-51) by 64 runs
David Masters claimed another five-wicket haul before Derbyshire's lower order fought back strongly to leave their Championship match against Essex fascinatingly poised. The Essex pace bowler finished with impressive figures of 5 for 51 from 30 overs but half-centuries from Ross Whiteley and Tom Poynton helped the Division Two leaders rally to reach 266.
Derbyshire's last three wickets put on 146 and Essex lost Jaik Mickleburgh in the fourth over of their second innings, but an attacking unbeaten half-century from Tom Westley carried the visitors to 85 for 1, a lead of 64 , at the close of day three.
Masters was easily the pick of the Essex attack and he took his third wicket of the innings when he had Wes Durston caught behind for 1 with only four added to the overnight total. At 32 for 4, Essex were in a strong position but no one else posed the same threat as Masters and Paul Borrington and Dan Redfern began the recovery in overcast conditions that favoured seam bowling.
The pair dug in for 15 overs and put on 60 before Borrington's disciplined innings of 42 from 99 balls was ended when he was struck in line pushing half forward at Masters. Redfern played some handsome drives but it was a loose stroke just before lunch that betrayed him when he edged Graham Napier into the hands of second slip.
When David Wainwright skied a drive to mid-off to give Masters his third five-wicket bag of the season, Derbyshire were in trouble at 120 for 7 but, just as in the Essex innings, an eighth-wicket stand put them back in the match.
Whiteley flicked Maurice Chambers, who proved expensive, over square leg for six on his way to his second fifty of the summer and Derbyshire had their first batting point in the bank before Tom Craddock beat Whiteley's attempted drive. But there was more resistance to come from the tail as Tim Groenewald joined Poynton to add another 34 runs in 10 overs and although Napier beat Groenewald for pace, Mark Turner helped Poynton secure a second batting point.
They scored 26 to give the home side an unexpected lead of 21 and Essex had only just wiped out the deficit when Mickleburgh was caught behind driving at Groenewald. Westley's driving was more productive as he plundered 10 fours in his 51 and with Owais Shah unbeaten on 26, Essex will go into the last day with a chance of forcing the victory they need to keep their slim hopes of promotion alive.