JAMIE Porter's career-best return of four for 20 propelled Essex to a three-wicket victory over Gloucestershire that revived their hopes of qualifying for the NatWest T20 Blast quarter-finals.

Requiring a win to move back into the South Group's top four, Gloucestershire posted a below-par 121 for eight - their lowest total of the season in the short format.

Varun Chopra top-scored with 44, smashing five fours and three sixes during the powerplay, as Essex reached their target with 3.4 overs to spare.

Omitted from the Essex line-up after proving expensive in the opening three matches, Porter came back in for Matt Dixon and grabbed his latest opportunity with both hands.

The 24-year-old right-arm seamer opened his account in style, inducing Gloucestershire talisman Michael Klinger to hole out to Paul Walter at deep square leg for nine.

He then returned to the attack in the 12th over to inflict further damage on Gloucestershire's middle order, removing Ian Cockbain, Jack Taylor and Kieran Noema-Barnett in rapid succession.

The only batsman to score fluently, Cockbain had harvested 32 from 25 balls when he succumbed to misjudgement, hoisting a length ball high to Walter on the mid-wicket boundary.

Porter struck again later in the same over, bowling the dangerous Taylor via an inside edge, and then held onto a return catch to send back Noema-Barnett, Gloucestershire's match-winner against Somerset in the previous game at Bristol.

Back in the side as one of Gloucestershire's two permitted overseas players, Australian batsman Cameron Bancroft added 49 for the third wicket with Cockbain, only to blot his copybook by chopping a short delivery from Walter onto his stumps after contributing 23 at a run a ball.

Once Porter had wreaked havoc on the middle order, Gloucestershire were heavily dependent upon all-rounder Benny Howell, who represented their last realistic prospect of posting a challenging total.

One of only four batsmen to clear the boundary, Howell made 20 before being undone by late swing and falling lbw to Pakistani paceman Mohammad Amir, who had earlier bowled veteran campaigner Phil Mustard.

Charged with the task of making the best of a bad job, Gloucestershire's tailenders found the going tough in the face of nagging accuracy from Amir and former England one-day specialist Ravi Bopara, who conceded just 41 runs between them from eight overs as the home side fell short.

In no mood to hang about, Chopra plundered 24 runs off one Matt Taylor over as Essex raised 58 for two from the powerplay to stamp their authority.

His violent 20-ball innings was terminated by a Chris Liddle yorker, while slow left-armer Tom Smith removed Bopara, Ryan ten Doeschate and James Foster inside two overs to offer Gloucestershire renewed hope.

But it was snuffed out by Walter, who batted with an assurance that belied his status as a lower-order batsman to see Essex home.