Alastair Cook bagged his second century of the new Specsavers County Championship season - this time wearing an England and Wales Cricket Board-compliant helmet.
The England Test captain, dropped on one by Danny Briggs, went on to hit 11 fours in his 189-ball hundred against Sussex at Hove.
It was the 52nd of his first-class career, and Cook finished unbeaten with 127 on the final day of this summer's second round of matches.
He did so, having reluctantly ditched the helmet he wore while making a century against Gloucestershire last week - in order to conform to new ECB safety regulations.
Cook could not quite help Essex to a second successive Division Two win as they closed on 266 for seven - in pursuit of 329 - after Jamie Porter had begun the day by joining his fellow seamer Graham Napier with a five-wicket haul as Sussex added only another six runs to be bowled out for 288.
Lancashire marked their return to the championship's top flight with an emphatic opening win over Nottinghamshire at Old Trafford.
After sitting out last week's first round, the Red Rose wrapped up their eight-wicket victory just before lunch.
The task was a simple one, after Neil Wagner bowled Lancashire into a position which required them to make only 86 in their second innings.
Jake Ball got rid of both openers early - to finish with six wickets in the match, to Wagner's 11 - but Alviro Petersen and Luke Procter sealed the deal in an unbroken stand.
Over the Pennines, champions Yorkshire had to settle for a stalemate in the first match of their campaign thanks to Hampshire's continued resurgence at Headingley.
The visitors added only three to their overnight 450 for eight - after number 11 Fidel Edwards had injured his ankle in morning warm-up and was therefore absent.
Then, though, Yorkshire found batting much more difficult second time round - following their first-innings 593 for nine declared with a much limper 183 for eight, as James Tomlinson took three for 31.
There were no winners either at Lord's, but another century for Middlesex's former England opener Sam Robson against Warwickshire.
Robson followed up his first-innings double-hundred with 106 this time, having hit 11 fours from 179 balls on the way to three figures.
The hosts closed on 304 for six declared, an innings most notable for the fact Ian Bell used all 11 bowling options - including wicketkeeper Tim Ambrose, who took a maiden first-class wicket when Australia Test batsman Adam Voges (92) was out to the final delivery of the match.
Back in Division Two, Leicestershire began their campaign with great promise in a 10-wicket win over Glamorgan at Cardiff.
Ben Raine finished with four for 57 as the hosts added another 19 for their last two wickets on the resumption.
Then, needing just 113 to win, Paul Horton (64no) hit a second successive half-century in his maiden championship match for Leicestershire since his winter move from Lancashire as he and Angus Robson coasted to victory in an unbroken century stand.
The run-fest draw at Bristol between Gloucestershire and Derbyshire ended with the visitors' second innings on 260 for two declared, with Chesney Hughes (137no) taking his match aggregate share to 233.
The opener put on 174 for the second wicket with overseas signing Hamish Rutherford (78), and passed three figures from 194 balls - having hit 16 fours.