Glamorgan are poised to claim their first LV County Championship victory of the summer after their pace attack, spearheaded by Adam Shantry, put Essex to the sword on the third day of their duel at Chelmsford.

Replying to a total of 515 for nine declared, the home side were bowled out for 200 in their first innings and finished on 133 for four in their second, still 182 short of avoiding an innings defeat.

Shantry was chiefly responsible for their troubles first time around as he underlined the value of line and length to claim five for 62 from 15 overs.

He began by finding a way through the defence of Varun Chopra to end an opening stand of 53 with John Maunders and went on to destroy the middle order with three wickets in 15 deliveries at a personal cost of six runs.

He did so by having Matt Walker neatly taken by wicketkeeper Mark Wallace, before getting rid of Mark Pettini and James Foster with successive deliveries.

Wallace again featured in the removal of Pettini while Foster was superbly caught low down in the slips by James Dalrymple.

Shantry followed these successes by ending the resistance of Graham Napier, this time with the help of a fine slip catch by Herschelle Gibbs.

John Harris, the 19-year-old paceman, underlined his promise by providing the main support with three for 37, including top scorer Maunders who was trapped leg before for 35, a dismissal that left Essex on 93 for six.

That the home side were to achieve some semblance of respectability was due to James Middlebrook and David Masters.

They took part in a partnership of 54 for the ninth wicket before Masters was removed by Garnett Kruger, again Dalrymple showing a safe pair of hands in the slips.

Essex were forced to follow on 315 behind and were soon plunged into trouble, this time David Harrison doing the damage by getting rid of Chopra and Maunders with only 17 on the board.

Harris and Robert Croft then struck to get rid of Walker and Pettini before the total moved into three figures to leave Essex in dire straights.

Their hopes of pulling off an escape of Houdini proportions rest either with a break in the weather or Hashim Amla, making his debut for the county, remained defiant for a greater part of the final day.

The South African will resume on 44 with Foster, the pair having so far added 48.