Sussex squandered a great chance to take control of the Pro40 League after a hugely disappointing batting display under the lights at Northampton last night.

They were bowled out for just 110 chasing a revised target of 144 in 34 overs after rain had delayed the start and there was a further ten-minute hold-up before their reply when the generator powering the temporary floodlights packed up.

Northampton's seamers maintained tight off stump lines and there was enough lateral movement to put serious doubt in the minds of the Sussex batsmen.

The home side's catching was faultless - the best effort a full-length dive at second slip by Stephen Peters to remove Carl Hopkinson just when he was threatening to wrest back the initiative.

The only time Sussex looked like chasing down their target was during a second-wicket stand of 39 between Matt Prior and Chris Nash. But from 42-1 the Sharks declined to 87-8 and there was to be no repeat of last Saturday's recovery in the C&G final success against Lancashire.

Perhaps the mental and physical effects of the last few days finally took their toll. Whatever the reason, Sussex need to regroup quickly with a crucial Championship match against Hampshire coming up at Hove tomorrow.

Essex are now in control of the Pro40 League and Sussex will have to win their remaining games against Middlesex and Nottinghamshire to have any chance of taking the title.

Sussex's batting wobble spoilt another excellent performance by their bowlers, notably Mushtaq Ahmed whose 5-25 were his best figures in one-day cricket for the county.

All of his victims were undone by googlies but perhaps the turning point was an unlikely last-wicket stand of 29 between Matt Nicholson and England's new find Monty Panesar which took their side to 148-9 and gave their seamers something to defend.

All of the previous seven day-night matches at Wantage Road have been won by the side batting second but it soon became evident that the record was under threat.

Richard Montgomerie had already played and missed several times when he sparred once too often at Ben Phillips in the fourth over to record a duck on his latest return to Northampton.

Prior briefly took up the attack with 30 off 33 balls including a towering six which sailed out of the ground over long on.

But he toe-ended the first ball from Steven Crook back to the bowler, Chris Adams mis-timed a drive to mid-on and Murray Goodwin was caught at second slip off a thick edge to give Crook the second of four victims in a career-best 4-20 which won him the man of the match award.

Nash looked secure enough until he also mis-timed a drive and when Sales took a second superb slip catch to remove Robin Martin-Jenkins, Sussex were 64-6 in the 17th over.

Hopkinson and Yasir Arafat added 21 but the end was nigh when Hopkinson drove against the spin in Panesar's first over and Luke Wright was bowled by Lance Klusener.

Arafat and Mushtaq gave Sussex hope but Crook trapped Mushtaq with the first ball of his second spell and the innings ended with a farcical run out when James Kirtley was stranded by a yard after Arafat sent him back.

Earlier, Chris Rogers and Usman Afzaal put on 60 in 15 overs but it all changed in the 16th over when Mushtaq came on at the pavilion end and immediately lured Rogers to his demise as the Australian came down the wicket but missed the googly.

Sussex's seam attack played their part too. Martin-Jenkins got the dangerous Bilal Shafayat for a duck. Wright had Phillips caught behind off an airy drive and at 119-9 Northants were in danger of falling to their lowest one-day score against Sussex.

Panesar has designs on moving up the England order even though he is still his county's No. 11 but he played the quicker men with as much assurance as any of his team-mates and when Sussex began tossing away their wickets the value of his contribution became more important.