Luke Wright scored the first double century of his career and rewrote the record books in partnership with Ben Brown as Sussex closed in on victory in their relegation battle with Worcestershire at New Road.

Wright brought up his double century off 255 balls with 27 fours and five sixes, surpassing his previous best of 189 against Durham at Hove last season.

The 30-year-old was unbeaten on 226 when the declaration came at 510-5 - a lead of exactly 300 - after batting for six and a quarter hours.

Then Worcestershire lost openers Brett D'Oliveira and Daryl Mitchell and their leading run-scorer Tom Fell in gloomy light as they reached 59-3 by the close.

Wright survived three dropped chances - on 118, 175 and 204 - but in between reeled off a series of powerful strokes and during his innings he completed 1,000 Championship runs in a season for the first time.

Wright and Brown (103) set a new record for the highest ever partnership by Sussex against Worcestershire for any wicket - 282 in 64 overs for the fourth wicket.

They surpassed the previous best stand of 226 by George Cox and Gordon Potter at New Road in 1954.

Skipper Chris Nash returned after Brown's dismissal - he was forced to retire with slight concussion yesterday - and made 90 before being trapped lbw by Leach.

In total Worcestershire dropped a total of five chances and they ended up with only one bowling point for the second successive match - a contrast to the maximum haul they had picked up in the first 12 matches of the campaign.

Sussex resumed on 251-3 with Wright on 98 but he needed a further 25 balls to complete his second hundred of the campaign from 166 balls with one six and 17 fours.

Wright and Brown scored freely with the latter completing his fourth Championship hundred of the season from 179 deliveries with eight fours.

There was a welcome breakthrough for Worcestershire when Brown was caught at deep backward square by Saeed Ajmal off Charlie Morris.

Nash then came back to the wicket and he also batted fluently in adding 104 in 17 overs with Wright before his dismissal - and the declaration came shortly afterwards.

Worcestershire went in with 35 overs remaining in the day and Steve Magoffin broke through in his second over when trapping Brett D'Oliveira lbw for nought.

Mitchell, who had been absent during the morning session to attend the birth of his second child, added 39 with Tom Fell as the fading light forced Sussex to turn to spin.

But it did not stop Sussex enjoying a quickfire double success with Mitchell (10) and Fell (26) both well caught at slip by Chris Jordan off Luke Wells and Ashar Zaidi respectively.

Bad light halted proceedings with nine overs remaining.