Worcestershire produced a spirited fightback on day two against Essex, reaching the close on 163-3 in their second innings with opener Matt Pardoe unbeaten on 74.
Essex had posted a first-innings total of 351 to give them a lead of 249, after resuming on an overnight 199-4
Essex soon lost Ryan ten Doeschate and James Foster before Graham Napier joined Ben Foakes to revive the innings.
The pair added 92 before Foakes was bowled by paceman Alan Richardson immediately after lunch for a 71 that included nine boundaries.
By that time, Napier had reached his half-century but he was to be left stranded on 64 as David Masters, Monty Panesar and Reece Topley were sent back in the space of four deliveries, Shantry claiming the last two with successive balls on his way to 3-76.
But it was Richardson who emerged as Worcestershire's most successful bowler, picking up 4-92 in 26 overs.
Faced with a daunting deficit of 249, skipper Daryl Mitchell and Pardoe were to provide the ideal platform for a Worcestershire fightback, although they needed a slice of luck early in the innings.
Pardoe had made just six of the 21 on the board, when he was put down by Nick Browne at third slip off Napier and he was to make good his escape by helping Mitchell take his side beyond their first innings total of 102 without a setback.
Mitchell was to reach his half-century with four successive boundaries off Topley and looked so at ease that it came as something of a surprise when he was dismissed with the total on 113.
He had contributed 62 when a sweep against left-arm spinner Panesar looped up into the hands of first slip Owais Shah.
Pardoe moved to his half-century from 120 deliveries with the aid of seven fours but was to lose two more partners.
Moeen Ali, after driving off-spinner Greg Smith for six was undone by Panesar when he dabbed a simple catch to Shah at first slip after making 21.
Tom Fell followed him back to the pavilion, an lbw victim of Smith, leaving Pardoe with the task of performing heroics if Worcestershire were to deny Essex their fifth Championship victory of the campaign.