Four Essex batsmen made half-centuries as they reached 329-4 and Glamorgan were made to pay for losing the toss.

England's Alastair Cook was dismissed second ball by Alex Wharf but Mark Pettini and Varun Chopra, who both made 86, put on 165 for the second wicket.

Pettini was eventually stumped by Mark Wallace off Robert Croft, and the same combination removed James Foster (7).

But Ronnie Irani (84 not out) and Ryan ten Doeschate (55 not out) piled on the misery with an unbroken stand of 115.

Skipper Irani, who made centuries against Glamorgan at Chelmsford in 2004 and 2006, hit 13 fours and unleashed some marvellous straight drives as Essex made light of their injury problems.

The county were forced to bolster their threadbare pace attack by re-engaging seamer Andrew McGarry, 25, who they had released at the end of the 2003 season, on a match-by-match basis - and he was included in their line-up.