If nothing else, Sussex are desperate to prove they are capable of sustaining a challenge for honours in both Championship and one-day cricket this season.

Too often in the past success in one form of the game has been to the detriment of the other and that worrying trend seems to be continuing.

Their rise to the top of the Championship has coincided with three successive defeats in the National League second division after they had lost once in their previous ten games.

The only consolation for the Sharks is that none of their rivals seem capable of cashing in on their sudden slump.

Durham missed the opportunity to overtake them at the top when they lost to Somerset yesterday so Sussex head across the Midlands today for tomorrow's match against Warwickshire with their two-point lead intact.

Meanwhile, beating Sussex for the second time in a fortnight has kept Leicestershire's own hopes alive ahead. They have leapfrogged Durham and Warwickshire into second place and victory over the Bears at Grace Road today would put them top.

The Foxes squeezed home off the last ball at Hove but this time there were seven deliveries to spare when Dinesh Mongia - the only batsman to show any sort of fluency on a desperately slow pitch - hit his eighth boundary in a competition-best 92, made off 93 balls and which also included a swept six off Mushtaq Ahmed.

Mike Yardy's 58 and a season's best 40 by Carl Hopkinson had at least gave Sussex a total to defend after their top four batsmen had gone with 44 on the board.

A target of 187 looked beyond Leicestershire when the dismissals of Aftab Habib and Jeremy Snape left them needing 85 off the last 15 overs.

But Mongia and Paul Nixon kept their nerve, posting an unbroken sixth wicket stand of 88 in 14 overs.

Crucially, Mongia was dropped on 41 when Murray Goodwin got both hands to a fiercely-struck upper-cut at backward point but failed to hang on. By Goodwin's normally high standards it was a bad miss and typified a Sussex fielding display which had too many rough edges.

Nine of the 21 runs they conceded in the first ten overs came when James Kirtley's shy at the stumps was missed by Prior and went for four overthrows and then Rana Naved bowled five leg side wides.

Hylton Ackerman, who made a match-winning century at Hove, would have been run out by half the length of the pitch had Hopkinson gathered cleanly at mid-wicket and there were too many lapses in the fielding, a point director of cricket Peter Moores seemed to be making behind closed doors afterwards.

A straw-coloured Grace Road pitch, fast outfield and cloudless blue sky promised a run feast yet it was anything but. Chris Adams probably figured batting would not get any easier on a sluggish surface which encouraged seam and spin alike and he was nearly proved right.

Once again Ottis Gibson proved Sussex's nemesis. A fortnight after taking 4-39 at Hove he returned 4-37 including two crucial wickets with the new ball.

Matt Prior failed to learn the lessons of their last meeting and was snared in identical fashion, holing out to mid off driving too early when the veteran West Indian held one back.

Goodwin offered no shot, Adams was trapped in front as Charl Willoughby slanted the ball into his pads and Richard Montgomerie tickled Darren Maddy's second delivery to the wicketkeeper.

Yardy and Hopkinson had rescued Sussex in similar circumstances against Kent earlier in the season and now they came good again.

The need to keep wickets intact meant they took few risks but they had still scored at exactly four an over when Hopkinson gave a return catch to Claude Henderson.

The Foxes' decision to bring Gibson back early paid dividends when Yardy was deceived by his slower ball after making his second totesport fifty of the campaign.

For once there were no fireworks from Rana Naved - Gibson's other victim - but Mark Davis smashed Mongia for two sixes, mocking Ackerman's decision to entrust two of the last three overs to his part-time spinner.

Sussex then got themselves into a winning position. Kirtley and Naved both struck with the new ball, Mushtaq Ahmed snared Ackerman in his second over and they were firmly in the ascendancy when Habib drove Yardy to cover and Snape was leg before to Martin-Jenkins.

Mongia rode his luck with several blows dropping just out of fielders' reach while Sussex were left cursing theirs. Now they desperately need a victory to calm fraying nerves under the Edgbaston lights tomorrow.