ENGLAND Test captain Alastair Cook scored an unbeaten 139 as Essex took control of their County Championship Division Two match against Derbyshire at a sun-baked Chelmsford.
The home side, though, were also indebted to some superb early bowling from David Masters, who took two wickets in four balls to unsettle the visitors — who had been looking to substantially build on their overnight advantage.
Essex had been hurried out for 94 on day one, but they hit back to dismiss Derbyshire for just 154 early, limiting the damage and clearing the way for Cook to show his class.
Essex got to the close on 297 for five, some 237 ahead going into day three.
Derbyshire had resumed with their lead at 45 runs on 139 for five, Shivnarine Chanderpaul unbeaten on 66 and Richard Johnson one not out.
But the visitors were immediately on the back foot as Masters made a breakthrough with the second ball of the morning when he bowled Johnson.
Masters then sent David Wainwright back to the pavilion for a duck after he edged a delivery behind to James Foster.
When the former Leicester-shire and Kent medium-pacer struck again to bowl day one hat-trick hero Tim Groenewald for two, Derbyshire were on the brink at 143 for eight.
Graham Napier saw off the tail as Mark Turner and Mark Footitt were both dismissed without scoring.
Only West Indian Chanderpaul had offered any sort of resistance, finishing unbeaten on 75.
Masters finished with six for 46, his 29th first-class five-wicket haul.
Essex were back at the crease just before noon, with openers Cook and Jaik Mickleburgh making steady initial progress.
Derbyshire finally got some joy from the first ball by off-spinner Wes Durston, who had Mickleburgh edging to the slips after making 24.
A single from Tom Westley saw Essex move on to 59 for one at lunch.
Following the restart, Cook, looking to put a disappointing winter Ashes tour behind him, went on to reach a 95-ball half-century, which included six fours.
Westley also passed 50, in just 70 deliveries, with 10 boundaries, before he was bowled by Groenewald for 56 to leave Essex at 161 for two.
Ravi Bopara offered support to the England skipper as Essex moved their lead into three figures at 193 without further loss by tea.
Cook’s century finally arrived in the 61st over with Essex on 222 for two.
Derbyshire, however, produced a late rally as first Bopara fell two short of a half-century off the bowling of Wainwright, and Groenewald then quickly trapped Greg Smith for one, leg before with the new ball.
Masters lasted only four deliveries before he was out for a duck, caught at mid-off, to give the visitors a glimmer of hope.
A rapid 13 from Ben Foakes — with three fours — helped move Essex closer to 300.
Groenewald finished the day with an impressive return of three for 37 from his 18 overs, taking his haul to eight wickets in the match so far.