ALL-ROUNDER Robin Martin-Jenkins continued to play a major role as Sussex headed confidently towards a first win of the season against Glamorgan at the Swalec Stadium.

At the end of day three, Glamorgan had been reduced to 51 for three in their second innings after Sussex had set the home side an unlikely 405 to win in a minimum of 122 overs.

Martin-Jenkins followed up his three for 65 in the first innings with an unbeaten 33 from 41 balls and then claimed two more wickets in Glamorgan's second innings.

Resuming their second innings on 65 for one - an overall lead of 158 - Sussex had set their eyes on batting Glamorgan out of the game.

But although they built on their useful lead, they did lose four wickets before lunch.

The mini collapse started when Robert Croft had opener Chris Nash well caught at slip by Jamie Dalrymple, who dived to his right to make a one-handed catch.

Only four more runs had been added when night watchman James Anyon was bowled by slow left armer Dean Cosker attempting to drive.

The reintroduction of James Harris into the attack proved profitable as he claimed Joe Gatting leg before and Luke Wright in the space of three balls.

Wright's expansive shot saw Jim Allenby launch himself to take the catch at first slip as Sussex stumbled to 126 for five.

It was left to Michael Thornely, who past his previous best first-class score, and Murray Goodwin to reassert Sussex's dominance.

The sixth-wicket pair guided Sussex to a 300-run lead with Goodwin reaching 50 from 71 balls.

After an unbroken spell of spin, seamer Chris Ashling was introduced into the attack and he accounted for Goodwin, bowling him with a yorker 17 short of his century.

But Thornely continued and was homing in on a maiden County Championship fifty before being adjudged lbw to Cosker.

And with the new ball Harris struck as Andrew Hodd was snaffled at cover point as Sussex reached 294 for eight at tea.

Harris claimed the scalp of Monty Panesar to claim his second four-wicket haul of the match shortly before Sussex declared, leaving Glamorgan to survive 26 overs of the third day.

But Sussex soon made inroads as Will Bragg departed lbw in Corey Collymore's third over and Martin-Jenkins claimed two wickets in 16 balls.

First Gareth Rees was caught behind before Dalrymple edged to first slip as Glamorgan slumped to 34 for three.