Durham 445 for 4 (Robinson 146* Lees 113, Bedingham 65, Ackermann 58*) vs Essex
Alex Lees and Ollie Robinson's contrasting centuries saw Durham pour a deluge of runs down on Vitality County Championship title rivals Essex.
Opener Lees commanded the crease in his 113, while Robinson took the bowlers on with gusto for an unbeaten 146 - both grabbing their second hundreds of the campaign.
David Bedingham missed out on a fifth three-figure score on the bounce but assisted the milestone-makers with a sublime 65, as he passed 800 Championship runs this year.
Essex's only positive on an otherwise dispiriting day, was overseas debutant Eathan Bosch claiming two wickets as Durham racked up 445 for 4.
Durham elected to bat first on a pitch previously used for two T20 matches, and set about their work in lively fashion, after Essex legend Keith Fletcher had rung the five-minute bell.
Michael Jones returned from Scotland duty to make his first Championship appearance of the season and blazed his way to 38 from 29 balls at the top of the order.
His aggression came to the fore with Simon Harmer's 10th-over introduction, with two sixes and two fours within the South African's first seven deliveries, as 16 came off the spinner's opening over.
If Harmer's early introduction was muted, Essex new boy Bosch's was electric.
The South African fast bowler has arrived on a four-match deal, with Sam Cook absent with a hamstring injury, and struck with his second ball when Jones loosely drove behind.
Bosch's curtain-raising wicket maiden was followed four overs later by the scalp of Scott Borthwick - who also edged behind to give Michael Pepper his second catch. His first five-over spell returned 2 for 25.
But from then on, the blue skies, humid weather, fast outfield and a flat pitch made the Cloud County Ground, Chelmsford a batting paradise. With those conditions, Bedingham didn't need a second invitation to cash in.
The South African was in the form of his life before the Vitality Blast interrupted the red ball season, with four successive centuries.
Only Michael Hussey and Kumar Sangakkara had scored five Championship tons in a row, and when he strode to a 53-ball half-century, three figures looked inevitable.
Bedingham is the leading run scorer in the country but at 860 runs in the season, and 65 on the day, he was Pepper's third victim, this time via Harmer's off-spin, to end a 95-run stand with Lees.
Quietly around Jones and Bedingham's gung-ho style, Lees was amassing his runs.
There was an odd stylish chip for six, and a few nervy edges over and wide of the slips early on, but otherwise he was serene and demonstrated significant control.
His first century since the opening round came in 184 balls, with Robinson's fifty coming a ball later in a double celebration.
Robinson decided the Jones-Bedingham approach was more appropriate, as has been the case all season with a season strike-rate heading towards 90, and out-scored Lees 81 to 47 in their 136-run alliance.
Lees was lbw to Matt Critchley, but Colin Ackermann arrived to soak up the pressure for Robinson to reach his second hundred of the season, coming in 116 balls.
The second new ball didn't help Essex in the latter stages of the day.
Robinson swatted the first delivery for one of his four sixes, as he and Ackermann - who reached 58 at a canter - sauntered to the close with a 131-run partnership, 445 runs and four batting bonus points, on the board after day one.
