Sussex may have lost the winning habit in the Championship but cricket manager Mark Robinson is confident it will not harm their chances of a second title in four seasons.

The county's position at the top of the first division improved despite being frustrated by a combination of rain and Middlesex's tail-enders at Southgate on Saturday.

Sussex took five of the six wickets they needed in the final session but Chris Silverwood defended the last two balls from Yasir Arafat and umpire Barry Duddleston then called time with the Sussex players in position to bowl another over.

Lancashire's defeat by Kent on Friday means Sussex stretched their advantage at the top to 13 points and they are 25 ahead of third-placed Kent.

Hampshire, who like Lancashire have a game in hand on the leaders, trail Sussex by 34 points but cannot be discounted.

After winning six of their first eight games Sussex have now been held to frustrating draws in the last two but Robinson remains upbeat.

He said: "The positives are that in both this game and Kent last week we have gone close on both occasions on two very flat pitches when we have perhaps not had the rub of the green.

"But we are still playing good cricket and have started to pick up more bonus points, particularly in batting, and have guys in form. People will talk about the various permutations at the top of the table but all we are worrying about is our-selves. Another county could put together the sort of run we had in the first half of the season but we still think we've got a very good chance.

Lancashire visit Hove for what will undoubtedly be billed as a title decider on Wednesday week but skipper Chris Adams believes it is a four-horse race.

He said: "We're pleased Kent beat Lancashire obviously. Lancashire were everyone's favourites at the start of the season, Hampshire are always dangerous with Shane Warne and Kent bat capably. There are four teams in it.

"But we have played really good cricket all summer and deserve to be in the mix. What we need is for our key performers to stay fit."

Mushtaq Ahmed's rusty bowling in Middlesex's first innings, when he failed to take a wicket for only the third time this season, was understandable after 17 days out with sciatica during which time he was unable to do any training.

But the leg-spinner was back to his effervescent best on Saturday with 3-74 including the key wickets of Owais Shah and Ed Joyce in the same over.

Sussex expect Mushtaq to be available on Thursday when they travel to Edgbaston to face Warwickshire, having still heard nothing from Pakistan about a possible call-up to their squad for the second Test.

In the end it was the loss of 24 overs to heavy showers after lunch rather than umpire Duddleston's suspect time-keeping which cost Sussex the chance of victory.

When play resumed after tea Middlesex, whose original target was 421 in 96 overs, were 138-4 with Nick Compton cruising towards a hundred and only 32 overs to survive.

But off-spinner Ollie Rayner gave Sussex hope when he picked up Scott Styris off a top-edged sweep and had David Nash caught at silly point.

Jason Lewry removed top scorer Compton for 86 as the batsman offered no shot and Middlesex were starting to panic when Arafat, who again bowled superbly, returned to the attack to win a leg before verdict against Chris Peploe.

Irishman Eoin Morgan, who had defied Sussex for nearly an hour, then nudged Mushtaq to silly point.

But with the clock showing 6.04pm and the fielders hurrying into position to squeeze one more over in Duddleston whipped off the bails despite the protests of a clearly disappointed Adams.

Robinson said: "The scorers had a minute left on their clock and that's what it said on the main clock. It was very frustrating But it was a fantastic effort to get five wickets in that last session."

Sussex start their Pro40 League division one campaign against the Bears at Hove tomorrow (4.40pm).