Sussex Sharks picked up their first Twenty20 Cup win at the final attempt

and silenced a packed house at Chelmsford in the process.

The majority of a 6,000 crowd had turned up hoping and expecting to see hosts Essex Eagles see off the bottom team in the South Group and clinch a home tie in Monday's quarter-finals.

Instead they were left waiting anxiously for confirmation they had gone through at all on run rate after being comprehensively outplayed by a Sussex side for whom this was a first ever away win in the competition.

Chris Adams and Matt Prior guided them home with nine wickets and 18 balls to spare, expertly compiling an unbroken second-wicket stand worth 112 in 11 and a half overs after Ian Ward had gone early.

It was a stunning performance by the Sharks, though Essex sneaked through to the next stage when the calculations were complete, albeit facing an away tie.

Prior led the Sharks home, hitting 11 fours, then completing the win with a straightdriven six off Andy Clarke.

He faced just 49 balls for his 68 while Adams collected his 38 off 33 deliveries, helped by five fours.

Three of those boundaries came off a single Graham Napier over immediately after the same player had dropped the Sussex skipper off a tough diving chance at point.

Adams was also put down by Scott Brant right at the death but otherwise there were precious few alarms once Ward had been held at third man after edging an expansive drive.

Quite how this sparks Sussex into life for the rest of a faltering season might be seen when they resume their National League campaign at Derby but last night's event in Essex must represent one of the highlights of their summer.

Essex knew midway through their innings that they were almost guaranteed a place in the last eight thanks to results coming in from elsewhere.

But their hopes of home advantage in the quarters were kept in the balance as Sussex produced some tight bowling and fabulous fielding.

Jason Lewry bowled his four overs economically on the start, making the breakthrough when Will Jefferson edged to slip, and Mushtaq Ahmed's impressive figures of 1-19 would have been even better but for two cleverly improvised boundaries by Mark Pettini from the spinner's last four balls.

When James Middlebrook opened the next over with a straight six off Luke Wright, it was the only moment of the night when it seemed Essex might take command.

Instead, Lewry replied with a superb one-handed catch when the same batsman clubbed the following delivery, a full toss, to mid-wicket.

Mark Davis topped even that in the final over with a stunning diving effort behind point to end an eight-ball onslaught from Darren Gough.

Throw in a super catch running back from slip by Mike Yardy to hold a skyer off dangerous Napier, plus decent groundwork all-round, and Sussex had an all-round performance of which they could be proud.