The threat of relegation took on a more realistic guise for Yorkshire after Sussex took their turn to heap ridicule on the reigning Division One champions.

Yorkshire are not safe even at home this campaign, and the Headingley faithful were sent home just after lunch on fourth day after witnessing James Kirtley's second five-wicket haul of the match.

Bundled out for 125 after starting the day with all second-innings wickets intact, Yorkshire could not even make Sussex bat again to win.

It is their second defeat of the season by more than an innings and their fifth overall from six outings.

Sussex stand-in skipper Kirtley got the ball rolling in the opening exchanges, claiming the first four Yorkshire scalps before returning figures of five for 41.

Delivering

Yorkshire were 19 for two after Kirtley removed Craig White for seven and Michael Lumb (one), both delivering edges to wicketkeeper Matt Prior.

Matthew Wood then had his stumps levelled before Australian Simon Katich was adjudged leg before for 16.

Forty-seven for four became 57 for five when Victor Craven was bowled by Kevin Innes.

And the bowler picked up his second wicket of the innings when dismissing Anthony McGrath for 18 in the same way.

Robin Martin-Jenkins got into the action with the wickets of Chris Silverwood and Steve Kirby, leaving the prospect of Kirtley taking 10 wickets in a match for the fourth time as the only imponderable.

He did just that when he removed last man and stand-in captain Richard Blakey, the only one to offer anything by way of resistance with 28.

With that wicket Sussex notched their first victory of the season, and Yorkshire's reputation as the whipping boys of Division One is starting to stick.

Yorkshire: M J Wood, C White, M J Lumb, S M Katich, A McGrath, V J Craven, R J Blakey (Capt, Wkt), G M Hamilton, C E W Silverwood, R J Sidebottom, S P Kirby.

Sussex: R R Montgomerie, M W Goodwin, M H Yardy, P A Cottey, T R Ambrose, R S C Martin-Jenkins, M J Prior (Wkt), K J Innes, M J G Davis, R J Kirtley (Capt), B V Taylor.

Umpires: M J Harris and D R Shepherd