Yorkshire's blistering start to the season shows no sign of losing momentum, with Essex made to suffer as the First Division leaders demonstrated the potency of their batting line-up for the second time in little more than a week.
Led from the front by their confident new captain, Andrew Gale, who registered his second hundred of the season, Yorkshire could not match their 610 for 6 against Durham but 516 all out has given Essex plenty to do to avoid a second defeat of the season.
It did not help that they slipped to 32 for 3 in reply, with England opener Alastair Cook trapped leg before by a Steve Patterson inswinger for only seven. They were five down at the close, still 207 short of avoiding the follow-on.
Gale, 89 overnight, lost partner Anthony McGrath, who had completed his second ton of the campaign on Tuesday evening, without addition to the score but went on to reach 135 with 16 fours and a six before he was stumped going down the track to left-arm spinner Tim Phillips. Half-centuries from Jonathan Bairstow and Rich Pyrah swelled Yorkshire's total.
Kent's Joe Denly fell five runs short of a century against Warwickshire at Canterbury but a patient innings spanning three hours and 43 minutes will only advance his prospects of breaking into the England Test side, his innings ended only by a brilliant one-handed catch at slip by Rikki Clarke, who was among the wickets but could not stop Kent building a big first-innings lead.
Reduced to 17 for 3 after Kabir Ali produced a brilliant spell with the new ball at the Rose Bowl, Nottinghamshire were rescued by 40-year-old Ally Brown's 81 and Steven Mullaney's unbeaten 72 as they countered Hampshire's 300 all out with 274 for 7.
England captain Andrew Strauss had a close-up view of Matt Prior's unbeaten 123 as the Test wicketkeeper performed a one-man salvage operation for Sussex at Hove, where the runaway Division Two leaders had their worst day so far, bowled out for 217 by Middlesex after winning the toss.
It was not such a good day with the bat for Strauss, caught by Prior off a thin edge for 13 as he went to pull Rana Naved-ul-Hasan. Strauss has one half-century in nine innings so far.
Jack Shantry took a career-best 5-49 for Worcestershire at Leicester, where Australian left-hander Phil Jaques, who has three Test hundreds to his name, bagged his second pair of the season.