OPENERS Mark Pettini and Tom Westley both scored centuries as Essex inflicted a 152-run defeat on Warwickshire in their Royal London One Day Cup Group B clash at Chelmsford.

Pettini and Westley dominated against the visiting attack to pave the way for a total of 320 for five, one which proved well beyond Warwickshire's capabilities as they were bowled out for 168 in 40.2 overs.

It proved an unhappy return for former Essex batsman Varun Chopra. The Warwickshire captain was soon regretting his decision to insert the home side as Pettini and Westley launched the Essex innings with an opening stand of 191 in 34 overs.

To make matters worse, Chopra then suffered the ignominy of being out first ball when Warwickshire began their reply.

The Essex openers never looked in the slightest trouble as they handled pace and spin with equal comfort, producing a succession of drives, pulls and square cuts to progress at nearly a run a ball.

Respite only came when Westley was trapped leg before to off-spinner Jeetan Patel but not before he had amassed 108, his second List A century with the help of a dozen fours and a six.

Pettini has been overlooked at Championship level, with the form of Nick Browne relegating him to the sidelines. But he remains a key figure in the one-day format and showed why with a forceful 126 from 127 balls before he swung Oliver Hannon-Dalby to deep mid-wicket and was fourth out in the 48th over after striking 10 fours and two sixes.

Before Pettini's demise, Ravi Bopara also struck two sixes while gathering 39 from 33 balls before he dragged on against Chris Woakes.

The Essex innings finished on a high when Ryan ten Doeschate struck the final delivery over long-on for 6 while gathering an unbeaten 21 off 12 balls.

Faced with such a daunting task, Warwickshire desperately needed to start their reply on a firm foundation but their hopes of doing so were soon shattered.

Chopra was caught and bowled by Reece Topley, an inside edge finding its way into the bowler's hands via the batsman's pad. The tall left-arm paceman soon claimed another wicket, that of Will Porterfield, when the opener holed out to deep square leg.

Only 37 runs were on the board when Tim Ambrose became the third man out when he clipped Graham Napier to third man where David Masters pocketed a catch in the 13th over.

By the halfway stage, Warwickshire had limped to 92 for five, by which time Rikki Clarke and Laurie Evans had been despatched to the pavilion leaving Jonathan Trott to salvage a little bit of pride for his team.

By then, however, he was fully aware that victory was out of the question for last season's beaten finalists but he did make something of a fight of it.

Trott reached his half-century by pulling Bopara for six but was out immediately afterwards for 51, made from 79 balls, when Kishen Velani took the third of his four catches at deep square leg to give off-spinner Westley another wicket and leave the Bears on 101 for six. It had been the same combination that got rid of Clarke.

Although the tail wagged, putting on a further 67 runs in 13 overs, Essex were able to celebrate a comfortable victory and gain consolation for the misery Warwickshire inflicted upon them last season when they triumphed at Chelmsford in both the Royal London Cup and Twenty20 Blast at the quarter-final stage.

Westley said: "I wouldn't say it was a difficult wicket but we had to work hard for the runs so to put on 191 with Mark (Pettini) for the first wicket was very rewarding. That set the platform for others to come in and finish the job off. Then the way the bowlers backed that up was fantastic."

Warwickshire director of cricket Dougie Brown said: "Essex played very well but was a still a disappointing result, more so because we failed to reach the standards we set ourselves."