When Dimi Mascarenhas took the wicket of Tim Ambrose yesterday morning, you could have heard a pin drop.

That told its own story, Hampshire were already as good as down.

Ambrose had, with Richard Montgomerie, added 26 runs to the Sussex overnight score of 399-3 before he cut tamely to point, where Will Kendall took a simple catch.

But there were no high-fives and no whoops of delight, not until Montgomerie was finally dismissed for a career best 196 13 overs later.

Sussex's opener edged a defensive prod behind after James Tomlinson angled the ball across the former Northants batsman for his fifth championship wicket.

Montgomerie, who was 168 overnight, had just surpassed his previous career best of 192 and, when he departed, Hampshire's survival prospects, which required a win, looked as dim as ever - Sussex were 460-5.

Hampshire's bowling was not much better than on day one and the Sussex batsmen continued to feast in glorious batting conditions.

Mascarenhas, the most tenacious of the Hampshire attack the previous day, went for five an over yesterday and came in for particular punishment from Matthew Prior.

Sussex's highly-rated wicketkeeper scored his maiden first class hundred off just 105 balls before Chris Adams declared.

The Sussex skipper would have been delighted with his side's 631-5.

That is the highest innings total by either Hampshire or Sussex in past meetings and it surpassed the 552-7 Sussex made at Portsmouth 98 years ago.

It is a record that will last for at least another year - these sides will, barring a miracle, be playing in different divisions next year.

Prior, together with Robin Martin Jenkins, added insult to injury by putting on 120 for the sixth wicket in 25 overs before the latter edged to slip, prodding forward to become Kendall's third first class victim of the season.

The 20-year-old smashed two sixes during his onslaught, carving Mullally over point and on to the pavilion roof and sending another maximum over mid wicket off Mascarenhas.

Mascarenhas was smashed for 18 off one over by Prior and Martin Jenkins as the pair brought up the 100-run partnership and Prior took Sussex past the 600-mark in audacious fashion, reverse sweeeping Udal to the boundary.

But it was against the off-spinner that his runs dried up when he had made 99.

He batted out a tantalising maiden from Udal and faced a total of 13 balls without scoring while one short of a memorable first ton.

Prior finally reached the milestone by on-driving Udal for three, having survived a strong shout for lbw from Udal, and then Adams called his men in.

The Sussex total must have looked like a mountain climb to Neil Johnson and Jason Laney as Hampshire's opening pair walked out to the crease.

But Johnson did what he does best, smashing a run-a-ball 51 before he poked at a good delivery from Martin Jenkins. There was some doubt as to whether he edged the ball but Hampshire's fate was decided on day one.

Jimmy Adams walked out for his first championship knock as Johnson departed but Laney accepted the light before the 21-year-old had reached the square and torrential rain soon followed.

That summed up Hampshire's season.

SCOREBOARD:

Overnight: Sussex 399-3 (R R Montgomerie 168 no, M W Goodwin 119).

SUSSEX

First Innings (cont)

R R Montgomerie c Pothas b T'linson 196

T R Ambrose c Kendall b Mascarenhas 32

R Martin-Jenkins c Johnson b Kendall 64

M J Prior not out 102

K J Innes not out 17

Extras (b7 lb8 w10 nb14 pens 0 ) 39

Total (6 wkts dec, 156 overs) 631

FoW: 1-193, 2-264, 3-349, 4-425, 5-460, 6-580 Did Not Bat: M J G Davis, R J Kirtley, B V Taylor. Score at 130 overs: 5-485

Bowling: Mullally 28-6-82-0, Tomlinson 30-5-154-1, Mascarenhas 31-8-114-2, Johnson 19-3-78-1, Udal 34-7-121-1, Adams 3-1-21-0, Kendall 11-1-46-1

HAMPSHIRE

First Innings

N C Johnson c Prior b Martin-Jenkins 51

J S Laney not out 14

Extras (lb2 w2 pens 0) 4

Total (1 wkt, 15.3 overs) 69

FoW: 1-69

To Bat: J H K Adams, R A Smith, J D Francis, W S Kendall, N Pothas, A D Mascarenhas, S D Udal, A D Mullally, J A Tomlinson.

Bonus Pts: Sussex 5 Hampshire 1

Bowling: Kirtley 5-0-22-0, Martin-Jenkins 7.3-2-27-1, Taylor 3-0-18-0

Umpires: V A Holder and B Leadbeater