Indian leg-spinner Piyush Chawla revived Sussex's hopes of avoiding relegation from Division One of the LV County Championship with four wickets on the first day of their relegation battle against Yorkshire at Hove.

Chawla finished with four for 82 from 37 overs as the visitors, who began the day only four points above Sussex in the table, failed to take advantage of batting first despite half-centuries from Adam Lyth and Andrew Gale. They closed on 274 for seven.

Acceleration was often hard work for the Yorkshire batsmen on a low, slow pitch offering some turn as Chawla probed away from the sea end, bowling the majority of his overs into a stiff breeze.

Sussex made an important breakthrough with the third ball of the match when Jacques Rudolph, Yorkshire's leading scorer in the Championship this season, was out lbw to Jason Lewry in what is likely to be the 38-year-old medium-pacer's final appearance at Hove before retirement.

Chawla came into the attack in the 15th over and struck in his second as Joe Sayers wasted an hour of careful reconnaissance when he was stumped after coming down the pitch trying to hit over the top.

Lyth hit 10 fours including successive boundaries off Dwayne Smith to reach his second half-century of the season before he was trapped by Corey Collymore but Chawla did the main damage, starting with two wickets in three overs after lunch.

Yorkshire skipper Anthony McGrath propped forward to a leg break and was smartly taken by wicketkeeper Andrew Hodd to give the 20-year-old his 200th first-class victim and then Jonathan Bairstow failed to read Chawla's googly and fell for a 16-ball duck.

It was hard work keeping the scoreboard ticking over against accurate bowling and both Gale and Gerard Brophy had moments of good fortune when mis-timed drives dropped just out of the reach of fielders while Rory Hamilton-Brown failed to hang on diving to his right when Brophy edged wide of second slip on 19.

The sixth-wicket pair added 56 in 23 overs but Chawla picked up his fourth wicket when Brophy offered no shot to a googly while Hamilton-Brown took only his second Championship wicket of the season with his off-breaks to end a promising innings by Gale.

The left-hander passed 50 for the sixth time this season and had looked comfortable, facing 178 balls and hitting eight fours in more than three hours until he drove to short cover playing forcibly off the back foot.

Scoring against the new ball was always easier and in the final hour Ajmal Shahzad and David Wainwright, whose maiden Championship hundred in the corresponding fixture last season effectively saved Yorkshire from relegation, added an unbeaten 65, the highest stand of the innings so far, for the eighth wicket to leave the contest evenly poised.