Matt Prior admits he is already thinking about Sussex's big day at Lord's.

Prior made a brisk 37 as the Sharks limbered up for their biggest one-day game in 13 years by fulfilling fixture obligations in the new Four County Twenty20 last night.

Sussex will not be at all worried about a fourth successive defeat to Essex, for whom Ravi Bopara made 98 off 52 balls to guide them home by seven wickets at Hove.

The Sharks rested some more experienced players, gave Chis Nash a chance to open and put Andrew Hodd behind the stumps while Prior enjoyed a short net before fielding in the deep.

Inevitably, the whole thing felt like a C&G warm-up for Sussex, who tackle Lancashire on Saturday.

And Prior admits that game is already dominating waking and sleeping hours.

He said: "I came in before the game and said Oh dear I've started to have dreams about Saturday'.

"It seems I'm one of the last.

"A few of the guys started a few weeks ago. We're all thinking about it but that is part of your preprations.

"It was nice to have an opportunity to blood a few younger guys.

"But I was out on the boundary and I heard the odd shout of I hope we do better on Saturday' and things like that.

"I think what people have to realise is I would rather lose this and win on Saturday.

"One of the key things is winning when there is something when there is really on it.

"Saturday is when we have to peak, not Tuesday in a friendly Twenty20."

Sussex took consolation from a crowd of about 2,500 in an event which, after all, is all about cashing in on the popularity of cricket's shortest format.

That is all good revenue and the punters seemed to enjoy the evening, though it lacked any of the intensity of this season's previous one-day battles between these two counties.

Essex were able to have chuckle when Bopara's misfield turned a single into a four and Ronnie Irani posed for the crowd after a diving stop off the next ball.

For once Sussex removed Irani cheaply when he batted, thanks to a great catch by Nash diving forward at short mid-off.

Mark Pettini was well held above his head at cover by Luke Wright off the last ball of the first over and Robin Martin-Jenkins needed just three deliveries to get the Essex skipper.

But Bopara and James Foster guided the Eagles home.

Bopara took four fours, and 22 runs in all, off a single Jason Lewry over and added legside sixes off Martin-Jenkins and Yasir Arafat.

Foster hit two sixes off Martin-Jenkins to the short legside boundary as Essex cantered home with 19 balls to spare.

No one player dominated the Sussex innings after they chose to bat first though Prior produced most of the fireworks.

He took 24 off Ryan ten Doeschate's second over by hitting the only two sixes of the innings, both over long-on, and three fours.

Prior faced just 20 balls but his departure was an anti- climax, tamely flat-batting an awful short ball from Bopara straight to short cover.

Arafat, coming in up the order at three, produced a couple of cracking drives off Bopara on his way to 21 off just 19 balls.

He is the sort of man who might fancy a tense run chase in fading light on Saturday evening.

Nash batted through two-thirds of the innings for a run-a-ball 42 but, other than a brief flurry from Martin-Jenkins and Carl Hopkinson, Sussex struggled to accelerate late on.

They lost three wickets for two runs in five balls at one stage.

Essex will fancy themselves to reach the final now by winning the return match at Chelmsford tomorrow.

But they would rather be in Sussex's shoes.