Sussex's Championship credentials were tested yesterday as Warwickshire rediscovered the batting prowess which took them to the title last season.

The Bears' success in 2004, when they won only five games, was based on running up huge first innings totals to insure themselves against defeat.

Skipper Chris Adams was expecting to turn up and find groundsman Steve Rouse had prepared a green top, judging by the look of the pitch on Tuesday when the sides met in the totesport League.

Instead, it turned out to be the flattest Edgbaston wicket of the summer so it was a day for Sussex's attack to sit in, maintain disciplined line and lengths and wait for mistakes after Adams had lost the toss.

They can be satisfied with their day's labour with only Rana Naved going wicketless as Warwickshire, fortified by Jonathan Trott's fourth hundred of the season, reached 329-7 when bad light ended play six overs early.

Trott gave his only chance on 101 when Adams spilled a straightforward opportunity at slip off Luke Wright and he will resume today on 130. How much the captain ends up regretting that miss depends on Sussex's ability to run through the tail this morning.

At least Adams and his players only needed to glance at the skies to ruminate that things seem to be running their way as the tightest Championship tussle for years enters the final straight.

While it belted down most of the day in nearby Balsall Heath, Bournville and Bewdley, the black clouds miraculously skirted their way round Edgbaston. Sussex are entitled to feel they are owed a break from the weather gods after losing the equivalent of seven days play to rain so far this season.

Warwickshire put together four decent partnerships but nothing bigger than the 78 lodged by openers Nick Knight and Ian Westwood.

Every time it looked as if the batsmen were getting on top Sussex seemed to be able to conjure up a wicket.

Indeed, when they took three in eight overs in mid-afternoon to reduce Warwickshire to 215-5 they were in the ascendancy.

But the patient Trott would not be budged.

In fact the South African's only alarm before he was reprieved by Adams came when he offered no shot to the second ball he faced and was struck on the pads.

To Rana's utter disbelief, umpire David Constant concluded that it had pitched just outside the line.

An easy-paced pitch offered few terrors and once established Trott was able to play through the line with confidence, collecting the majority of his 17 boundaries with punched drives through the off side.

If someone had been able to stay with him any length of time Sussex could have been in trouble, but Alex Loudon, Tony Frost and Dougie Brown both got out when seemingly well set.

Warwickshire captain Knight has been a thorn in Sussex's side regularly down the years and when he passed 50 for only the fourth time this season Sussex must have feared the worst.

He lost the impressive Westwood when Robin Martin-Jenkins, in the middle of an excellent spell from the City End, found some late inswing to take the inside edge.

But it was Wright, fit again after a side injury and preferred to off-spinner Mark Davis, who claimed the key scalp of Knight as the former England left-hander, in trying to run the ball down to third man, tamely steered it into the hands of second slip.

Trott and Loudon knuckled down but after putting on 68 for the third wicket Kirtley returned to unseat first Loudon and then Luke Parker with inswinging yorkers in a fiery five-over burst.

Michael Powell never looked comfortable against Mushtaq Ahmed and he was eventually put out of his misery, playing back to a leg break and giving silly point a straightforward bat-pad catch.

But there was no budging Trott and now Frost, another batsman who has taken delight in frustrating Sussex bowlers over the years, joined him in a stand of 58 in 18 overs either side of tea.

Trott, after spending ten nervous minutes on 99, duly went to his hundred off 157 balls in three and three-quarter hours and on 114 became the first Warwickshire batsmen to reach 1,000 runs this season.

He lost his partner soon afterwards when Wright was delighted to see Frost flick a leg-side half-volley straight to square leg.

The young all-rounder certainly justified his selection with three bustling spells from the Pavilion End and if there was any bounce to be extracted from the pitch it was usually Wright that found it.

Sussex took the new ball immediately it became available but their only success with it came when Brown gave Kirtley his third success of the day, caught at second slip after putting on 55 for the seventh wicket.