Hampshire 10 for 0 trail Essex 447 for 9 dec (Rossington 104, Critchley 99, Harmer 62, Yadav 51, Westley 50) by 437 runs
Critchley had been strolling towards three figures and 1,000 runs for the season but stuttered on 99 before he slapped to short extra cover.
Essex accrued three batting points in their quest to challenge Surrey for the title – which cancelled out the three bowling points Surrey picked up against Northamptonshire. The points difference remains 18.
Having resumed on 310 for six, and just eight overs into the second new ball, Essex had the 350-run bonus point in their sights.
Critchley was more watchful than he had been during his exciting 177-run partnership with centurion Adam Rossington.
He went from 83 in 123 balls to 99 in 162 balls before getting stuck. He batted out a maiden from Liam Dawson – which included him getting dropped off a caught and bowled.
Three more dots off Kyle Abbott followed as he struggled to find a gap in the field, before attempted to hit Dawson over the covers and was caught by Nick Gubbins at short extra cover.
Critchley had never had the misfortune of falling for 99 before, while he now has 969 runs for the season.
His departure sparked an up-turn in the tempo, as Harmer sparked into life and Yadav took a fancy to Dawson and fellow spinner Felix Organ.
They scored 77 runs in seven and a half overs before the declaration came – their 70 stand coming in 69 balls.
Harmer dominated his boundary hitting by rocking onto the backfoot and cutting behind point, although also pinged Dawson over long on after coming down the track.
The South African’s half-century came in 76 balls as he moved past 500 runs in a profitable season from the lower-middle order.
Yadav’s 51 off 45 was breathtaking. The Indian swung hard and far in his four sixes, and his three fours didn’t come from precision play either.
Harmer and Yadav were both caught at long on going for a big shot, with the latter’s bringing the end of the innings and lunch.
Sam Cook sent down three maidens in response, with Harmer’s sole over also runless.
Toby Albert and Fletcha Middleton’s 10 runs all came off Jamie Porter before bad light took the two teams off.
The forecast rain then battered the Cloud County Ground, Chelmsford and saw play called off just before 16.30.