Sussex head to Old Trafford on Sunday week knowing that only victory over Lancashire will guarantee their place in the first division of the National League.

They slumped to their second damaging defeat in the space of three days last night when champions-elect Gloucestershire eased to a six wicket win with 11 balls to spare.

Gloucestershire, chasing an unprecedented clean sweep of the domestic one-day honours, seemed to have got the rough end of Duckworth-Lewis calculations when they were asked to score 171 in 31 overs after two rain stoppages had curtailed the Sussex innings which closed on 148-8.

But victory never looked in doubt after Tim Hancock and Kim Barnett had launched the reply with a stand of 69 in 15 overs.

Skipper Ian Harvey blasted 43 off 30 balls, including 18 in one over off Mark Robinson, and Hancock made 51 from 72 deliveries before Jack Russell made sure the good work of the top order didn't go to waste.

All of which means Gloucestershire will be crowned champions if Somerset fail to win at Old Trafford tonight. Even if they do, Harvey's accomplished outfit will be lifting the silverware again at Bristol providing they beat Northamptonshire in their final game.

They have now won their last four one-day meetings against Sussex, including a semi-final and a quarter-final, and on this evidence Chris Adams's men are still a long way short of competing with them on equal terms despite the continued brilliance of Michael Bevan.

The Australian made an unbeaten 82 off 87 balls in their 148-8, keeping his head while others were losing theirs as Sussex surrendered five wickets in the last seven overs in the chase for runs.

It was Bevan's eighth half-century of the season in the National League and took his aggregate to 654 runs, raising his average to an awesome process.

He was unable to field after hurting his groin in the last over and Sussex must pray he makes a quick recovery. Their task at Old Trafford, even against a Lancashire side seemingly doomed to relegation, will be difficult enough without his contribution.

He came to the wicket with Sussex in trouble after Adams, chasing a wide one in the first over, and Richard Montgomerie, brilliantly taken one-handed at square leg, had both fallen to Harvey with just 12 on the board.

Rashid tempered his attacking instincts to help Bevan add 31 for the third wicket before he was deceived by James Averis's change of pace, but Bas Zuiderent and Bevan maintained their concentration despite the rain breaks to put on 55 in 12 overs before Hancock ripped out the Dutch-man's leg stump in his only over.

Sussex added 50 valuable runs in the six overs which remained after the second stoppage, but Bevan lost five partners in the process as Gloucestershire bowled and fielded like a side who expect to win every one-day game they play.

Will House drove to long off after making a rapid 19, Tony Cottey chipped his second delivery to short mid-wicket and in the last over Martin-Jenkins and Nick Wilton lbw to the impressive Harvey first ball.