Sussex ran into their usual trouble with the Law on the second day's play at Hove before Mushtaq Ahmed dragged them back into contention against Lancashire.

Stuart Law scored an unbeaten 171, his fourth hundred against the county since switching from Essex to Old Trafford three years ago, and was single-handedly responsible for earning his side a first innings lead of 140 after two days of the first real heavyweight clash of the Championship campaign.

There were one or two scares, but Ian Ward and Richard Montgomerie negotiated 19 overs before the close, reaching 51-0.

Admiring Law's seemingly effortless accumulation from his station at slip would only have reinfored Sussex skipper Chris Adams' view that the Queenslander has been the outstanding batsmen during his era in the county game.

In seven innings for Lancashire against Sussex he has now scored a remarkable 847 runs including a double hundred, three centuries and 96. The seven he made in the second innings at Hove last August, when Sussex won to take a giant step towards their first title, represents his only failure against the county.

Wednesday's cold and rain was replaced by sunshine and warmth yesterday and batting conditions were at their best. But, like all of the pitches at Hove last season, the dry surface always kept Mushtaq in appeals.

The little leg spinner is not Sussex's secret weapon anymore, but there is no evidence so far this season that batsmen - Law apart - have learnt to play him any better.

He needed 12 overs before claiming his first wicket when Carl Hooper, who had laboured patiently for 31 overs in making 34, was caught at silly point off bat-pad.

The former West Indies captain had helped Law add 109 for the fourth wicket and their duel with Pakistan's Mushtaq and Mohammad Akram in the hour after lunch provided the most compelling cricket of the day. Whether chairman of selectors David Graveney, scouting for future England talent, concurred is a moot point.

Mushtaq broke another important stand shortly before tea when his googly snared Glen Chapple who had contributed ten to a fifth wicket partnership of 57 with Law. Dominic Cork was trapped in front by Kevin Innes in the next over and after tea Mushtaq struck in successive overs.

Warren Hegg fell in identical fashion to Hooper to the third ball of the session and when he trapped Peter Martin half-forward, Lancashire's lead was not yet over 100.

But Law farmed the strike to such good effect that the last two wickets added a further 43 runs before Akram tidied things up by yorking Sajid Mahmood and thudding a straight one into Gary Keedy's pads.

This would have been the first sight of new signing Akram for most Sussex supporters and they must have been impressed.

The languid approach to the wicket is something of a smokescreen for Akram can make even the best batsmen hop about a bit while his ability to reverse-swing gives his captain another option when the ball gets old.

He regularly probed for Law's supposed weakness against the short-pitched ball although the Australian refused to take the bait until he had eased past 150 and swatted him disdainfully over long leg for the only six of his innings.

Akram epitomised a hardworking effort by the entire seam attack, of whom only Jason Lewry went unrewarded.

Robin Martin-Jenkins, whose rhythm impressed Graveney and fellow selector Rod Marsh in the morning session, made the first breakthrough when Mal Loye lost his off stump to a loose drive.

Innes's well disguised slower ball accounted for Iain Sutcliffe when he seemed well set, but the balance tilted firmly Lancashire's way when Law and Hooper came together either side of lunch.

Hooper, like most of the batsmen who followed him, never totally got to grips with Mushtaq, but unhinging Law was an altogether more difficult task. He reached the 68th hundred of a prolific career and then his 150 with the same shot, a delicate late cut through the gully which even Mushtaq would have admired.

The gap between square and mid on was found with uneering accuracy while any indiscretion in line outside off stump was ruthlessly punished. He hit 22 boundaries from 246 balls faced in five hours 22 minutes.