Monty Panesar's stingy four-wicket return kept Essex in their LV=County Championship Division Two fight at Worcestershire after Saeed Ajmal dominated the hosts' bowling.
Worcester spinner Ajmal cleaned up Essex's first innings with 6-75 as the visitors turned their overnight 52-2 into 203 all out on the second day at New Road.
The 36-year-old Pakistan slow bowler's hefty haul would have put Worcestershire in the box seat had Panesar not produced fine figures of 4-18 from 14.2 overs, including six maidens.
The hosts, who an 88-run first innings lead, slipped to 105-8 at the close - their lead of 193 meaning the result of this match remains in the balance.
Gloucestershire are closing in on a first Division Two victory of the season after compiling an imposing 351-run lead at the County Ground against Kent.
Day two of the match saw the hosts coast to 213-4 at the close of play, with Alex Gidman making 85 before succumbing to the bowling of Darren Stevens, while Hamish Marshall was not out on 66.
The match had looked well poised after the home side were restricted to 252 in their first innings, only for Kent to be skittled out for a paltry 114.
The visitors started the day on 33-6, still 219 runs behind, having lost six final-session wickets in a humiliating collapse. They faired moderately better when play resumed - resistance was offered by Sam Billings with 42 and Adam Ball's 37 - with James Fuller and Will Gidman spearheading Gloucestershire's assault with four wickets apiece.
Over at Grace Road, Division Two leaders Hampshire struck three times late on to snatch a modest advantage over Leicestershire.
The home side looked to be on course for a first-innings lead as they reached 187-3 in reply to 332 all out, only for a late clatter of wickets to reduce them to 296-9 - a deficit of 36 runs.
West Indian Ramnaresh Sarwan top-scored with 60, Angus Robson hit 54 and Rob Taylor scored 53, while South African seamer Kyle Abbott took 4-55 and new ball partner James Tomlinson ended the day with 3- =49.
Earlier, Leicestershire needed just 25 balls to clean up the Hampshire tail in the morning session, with Nathan Buck and Anthony Ireland swiftly getting rid of Abbott and Danny Briggs as Hampshire added just 11 runs to their overnight total of 321-8.
Former England Lions seamer Buck was the pick of the hosts' attack as he finished with figures of 5-84.