Sussex's seemingly unstoppable march towards National League promotion suffered a setback yesterday with only their second defeat of the season.

Leicestershire Foxes, fortified by Hylton Ackerman's unbeaten 113 and 93 by Darren Maddy, won by six wickets although the Sharks only surrendered an unbeaten run at Hove which stretched back to May 2004 when Ackerman hit the last ball to the boundary.

The Foxes had needed ten off the final over and with his seamers all bowled out, Chris Adams trusted it to Mike Yardy. It looked an inspired decision when Ackerman and Paul Nixon could only scramble three singles off his first four balls.

But Ackerman swung the fifth delivery high over the pavilion for six to tie the scores and pulled the last to the fine leg boundary. It was a captain's innings in every sense, his undefeated 113 coming off 127 balls with ten fours.

The Sharks remain four points clear at the top of division two and can be excused this slip-up.

They reacted to their only other defeat against Yorkshire three months ago by winning seven of their next eight games and it would still be a major surprise if they did not go up as champions.

Their score of 223-8 looked to be over par on a two-paced pitch and represented a pretty decent recovery after they had slumped to 86-5 halfway through their innings.

It appeared to be a winning total when James Kirtley took his customary wicket with the new ball and the outcome could have been different had Maddy not been given the benefit of the doubt when Kirtley, wicketkeeper Matt Prior and their team-mates were convinced he had gloved a catch before he had got into his stride.

But umpire John Steele's finger stayed down and Maddy stayed put to build what turned out to be the match-winning partnership with Ackerman.

Maddy hit ten fours and a six over mid-wicket off Robin Martin-Jenkins and was furious to fall in sight of his hundred, leg before playing across a straight one in the 38th over. But he had done his job in a stand of 185 in 36 overs, the highest for any wicket in matches between the counties.

Leicestershire needed 35 off six overs at that stage but the bowling, particularly from Kirtley, was tight and Dinesh Mongia and Aftab Habib both perished. Ackerman, though, kept his head while others were losing their's.

There were some positives for Sussex, not least a season's best 78 from Chris Adams.

The skipper has got used to watching his openers delay his own appearance in the middle this season but yesterday he was batting in the fifth over after Prior's dismissal and conditions were far from easy.

Prior, who spooned a catch to mid-off after launching into a big drive too early, was not the only batsmen to be frustrated by a relaid pitch used earlier in the season against Bangladesh.

Adams made it his intention to try and bat through and was as good as his word. He glued the innings together while cameos from Martin-Jenkins and Rana Naved, who smashed 45 off just 30 balls, at least gave the Sharks something to defend.

The new ball darted around and there was slow turn for the Foxes' spinning triumverate when it got soft and until Martin-Jenkins came in no one was able to offer Adams much support.

Richard Montgomerie was unfortunate to be run out backing up when David Brignull deflected Adams' drive onto his stumps in his follow through while Murray Goodwin could not believe he had been given out to a ball from Ottis Gibson which may have been drifting down the leg side.

Yardy had an airy waft and Carl Hopkinson was bowled round his legs but Martin-Jenkins took the confidence he must have gained from his 88 in the Championship win over Surrey last week into the shorter format.

His shot selection was good and 36 off 44 balls gave the innings much-needed momentum until he was snared by Jeremy Snape with eight overs left.

The real acceleration, however, was provided by Rana who dominated what was effective a stand of 67 off just 44 balls with his captain. It was a throwback to the days when another Pakistani used to throw the bat down the order on a Sunday afternoon in the Sussex cause.

Certainly Imran Khan would have impressed with his compatriot's show of strength and improvisation.

He struck three huge sixes and three boundaries while Adams moved quietly to a season's best before driving the last ball to long on to give Gibson his fourth wicket. Adams hit six fours in 110 balls faced and also passed 7,000 competition runs when he had made 19.