Essex 245 (Cook 84, Lawrence 61, Rhodes 5-17) v Warwickshire
Will Rhodes sliced through the Essex batting with four wickets in 26 balls either side of tea to claim career-best bowling figures of 5 for 17.
Sir Alastair Cook and Dan Lawrence had put on 116 for the third wicket before Rhodes came on for his first prolonged spell and had both batsmen back in the pavilion in quick succession to precipitate a major collapse from 157 for 2 to 171 for 6. Essex revived belatedly but were dismissed for 245 just before the close.
Cook was first to go, for a dashing 84, dabbing at a delivery outside off-stump, the ball lobbing tamely into Jeetan Patel's hands at gully. Lawrence followed soon after, edging behind another wide-ish delivery.
Rishi Patel was next, fencing outside off-stump to second slip, and four balls later Adam Wheater drove to Olly Stone at mid-off.
Rhodes, who had a loan spell at Chelmsford three years ago, had taken just one wicket previously this season for 150 runs. The part-time seamer's previous best figures were 3 for 42. Yet at the fall of Wheater's wicket he had claimed four wickets at a personal cost of two runs for Wimbledon-style figures of 6-4-6-4.
The carnage did not stop there. The parsimonious Oliver Hannon-Dalby, who had bowled six maidens in his first seven overs, took his first wicket of the innings when he trapped Simon Harmer lbw.
Ryan ten Doeschate had watched from the other end while the wickets tumbled, but after reaching 26 from 43 balls he gloved Stone to the wicketkeeper. And Rhodes returned at the end to have Aaron Beard flashing at a delivery and being caught behind.
Warwickshire's decision to settle for an uncontested toss and bowl first had looked ill-advised when Cook and Lawrence were still together six overs before tea. But with the ball in Rhodes's hands it suddenly looked a completely different proposition.
Lawrence was the dominant scorer in the 39-over partnership with the former England captain. His half-century came from 68 balls compared to Cook's comparatively pedestrian 122.
Lawrence had used his feet to good effect against Patel, lofting him over long leg for six that set the tempo for his exhilarating 105-ball 61. He hit nine fours, the seventh an effortless drive through the offside to bring up his fourth Championship fifty of the season.
Cook finished 16 short of celebrating his 300th first-class appearance with his 66th century. He mixed diligence with some elegant strokes, hooking, cutting and driving his 11 boundaries, during his 195-ball stay at the crease.
Henry Brookes had made early inroads with the first two wickets to reduce Essex to 41 for 2 from 20 overs. Nick Browne hung around for 48 balls for six before he chased one from Brookes outside off-stump and chipped straight to Rob Yates at backward point.
Brookes struck again three overs later when Tom Westley attempted to smash him over midwicket, only for Michael Burgess to mark his Warwickshire debut by pulling off a spectacular one-handed catch above his head.
Burgess, signed on an initial loan from Sussex, was drafted into the team along with promising teenage 2nd XI batsman Dan Mousley to replace Warwickshire's chief run-getters Dom Sibley and Sam Hain, both on duty with England Lions along with Essex seamer Jamie Porter.
Stone picked up his second wicket when he bowled Peter Siddle with a leg-stump yorker before the players were taken off briefly when it appeared the air ambulance would need to land on the outfield to attend to a sick spectator. That proved unnecessary and Aaron Beard and Matt Quinn continued a last-wicket stand worth 34, of which Beard contributed an impressive 29.