While Chris Adams cannot buy a run at the moment, team-mate Tony Cottey is in the best form of his Sussex career and how the county needed him against Leicestershire yesterday.

The 37-year-old reeled off the third century in his last four innings to negate the threat posed by a Grace Road pitch which is getting slower and lower and some typically canny seam bowling by Leicestershire skipper Phil DeFreitas.

Cottey followed up scores of 188, 107 and 98 in his last three knocks with 137 not out, becoming the first Sussex batsman since Michael Bevan three years ago to score hundreds in three successive matches.

While his top order colleagues struggled all day to time their shots, Cottey looked secure from the moment he heard the reassuring sound of his bat middling the first ball he faced from the wily DeFreitas whose figures of 3-34 in 11 overs did not flatter him.

DeFreitas took two of the four wickets to fall during the afternoon session which left Sussex 215-5 and the contest nicely poised.

Matt Prior joined Cottey to turn things around in an unbroken sixth wicket stand of 125, taking Sussex to 340-5 at the close, a lead of 20.

While Cottey is enjoying the purplest of purple patches, senior team-mates are struggling, so it was encouraging to see opener Richard Montgomerie post only his third half-century of the season.

In truth it was not a thing of beauty. Cottey gave him a 21 overs start but still beat him to 50 and it is hard to recall Montgomerie playing too many genuine attacking shots.

To bat for more than three hours and face 176 balls will have done his confidence a world of good and, if Sussex are to sustain their Championship challenge, they will need contributions from their senior men in the second half of the season.

Montgomerie lost his opening partner Murray Goodwin in the fifth over of the day when DeFreitas swung one back into his pads after Goodwin had failed to add to his overnight 34.

Just by bowling wicket-to-wicket and offering the batsmen no width whatsover, DeFreitas and Charlie Dagnall restricted Sussex to a mere 27 runs in the first hour, but respite came with the appearance of Leicestershire's two spinners, left-armer Rupesh Amin and Jeremy Snape whom Cottey milked with predictable ease on his way to a seventh half-century in his last eight innings.

Montgomerie had hit six boundaries when DeFreitas dragged his side back into the contest with two wickets in three balls after lunch.

A pearler which pitched on off and nipped back to hit middle stump ended Montgomerie's vigil after the second wicket pair had added 103 and, having surviving a confident leg before shout first up, Adams shuffled across one which held its line. Moments later he was heading for the practice nets with Director of cricket Peter Moores.

At last Leicestershire found someone to support the heroic deeds of their captain.

In his first over after replacing DeFreitas, Dagnall forced Tim Ambrose to play on via the thinnest of inside edges.

Ambrose stood his ground for several seconds in the belief that the ball had bounced back on to the stumps off wicketkeeper Paul Nixon before reluctantly trudging off.

When Robin Martin-Jenkins was defeated by a pea-roller from Dagnall, Sussex had lost four wickets for 54 in 16 overs and seemingly their stranglehold on the contest as well.

DeFreitas let them off the hook by allowing Cottey and Prior to accumulate off some unthreatening medium pace from Darren Stevens and John Maunders in eight overs before tea.

The new ball was taken straight after the interval but by then Cottey had eased to his hundred with 15 fours and a pulled six off Maunders over square and Prior was beginning to go for his shots.

DeFreitas and Dagnall gave it all they had, but despite poor light the batsmen began to dictate terms again. Prior's eighth boundary, edged fortuitously between wicketkeeper and slip, took him to his fourth half-century of the season while Cottey's untroubled accumulation continued at the other end.

When Brad Hodge came on for the last over he was the ninth bowler used by DeFreitas.

By then the sixth wicket pair had added 125 in 39 overs and Cottey had occupied the crease for a minute short of six hours, not bad for a 37-year-old in temperatures of 90 degrees.

Worryingly for Leicestershire, there was still the prospect he could push on and put his side in a position to force their sixth win of the season.

Sussex 340 for 5; Leicestershire 320 all out