Both Sussex and Yorkshire could escape relegation after Sussex closed 75 runs behind at 118-2 following on at Hove.

The defending champions resumed at 25-3 but opener Chris Nash struck his second first-class century to help muster 200.

That bonus point put Sussex above Kent, and when Yorkshire took 4-14 to dismiss the hosts for 207, their extra bowling points also put them on 155 points.

With Kent stuck on 154 and in trouble against Durham, defeat for Rob Key's team would send them into Division Two.

It was an anxious scrap for Sussex, who have lost only two previous matches so far this season but have become embroiled in the relegation fight after drawing 11 times.

On a delightful clear morning at Hove, Nash and Murray Goodwin began the rebuilding process after Thursday evening's calamitous start.

They had taken the score to 64 when Goodwin overbalanced slightly and was stumped down the leg-side by the nimble Gerard Brophy.

A major partnership was urgently needed and Matt Prior helped add 60 with Nash either side of lunch, until he cut to point where Richard Pyrah took a nonchalant one-handed catch.

When Chris Adams, in his final match as captain and possibly final innings for Sussex cut tamely to Pyrah in the same position to depart for an eight-ball duck.

That left Sussex 71 short of the magical 200 mark with only four wickets remaining.

Nash calmly reached three figures from 163 balls but with seven runs still needed for that bonus point, he succumbed to left-arm spinner David Wainwright's first delivery of the innings.

He pulled straight to short mid-wicket and Wainwright, who made his maiden first-class century on day two, continued his superb match by taking the final two wickets.

Michael Yardy, who takes over the captaincy next season, struck six fours and a six in an unbeaten 60 as Sussex improved in their second innings.

Nash edged Adil Rashid to slip and Carl Hopkinson was trapped by a Wainwright arm ball but Sussex will be confident of survival, if not in the match then in the division.

Yardy admitted that his side were not out of danger yet.

"We've got ourselves in a bit of a predicament, partly due to ourselves, partly to other situations," he said.

"It's key to just keep playing it as you would any normal game. It's easy to say that, harder to do it, but we will do.

"It's going to be nervy but we're aware of what we've got to do."