THE sun shone, but it was a dark day for Durham as they were rocked by news of Paul Coughlin's defection and punished for choosing to field first at home to Sussex.

They stuck at it, however, and by taking the last five wickets for 18 runs in 6.3 overs with the new ball they dismissed the visitors for 346 then reached eight for one.

Sadly, the good fortune Keaton Jennings had enjoyed in taking three wickets continued to elude him with the bat and he fell lbw to the last ball of the day.

Durham must be sick of the sight of Luke Wells, whose maiden century on this ground six years sticks in the memory for all the wrong reasons. He has improved sufficiently to score 258 against Durham at Hove this season and followed up with 122.

A lanky left-hander not dissimilar to Jennings, Wells enjoyed the sort of luck so conspicuously denied the Durham opener recently. But after playing and missing for the umpteenth time earlier in the over, Sussex's acting captain finally fell to an innocuous ball from Jennings, trying to turn it to fine leg and gloving to Michael Richardson.

It was the second of three wickets for Jennings on a day when the four seamers, including the pacy Brydon Carse, continually beat the bat without success after Chris Rushworth pinned Harry Finch lbw with the sixth ball of the day.

The decision to bowl first after a pointless toss continued to look sound when the ball was moving around in the early overs. But Wells and Kolpak signing Stiaan van Zyl, who played in 12 Tests for South Africa, could not be shifted.

Captaining Sussex for the the first time, Wells passed 1,000 championship runs when a four through mid-wicket off a Ryan Pringle full toss took him to 37.

The fact that Pringle was on for the 22nd over could be translated either as an admission that bowling first hadn't worked or an attempt to justify his inclusion after not bowling at all against Kent.

Considering how much they have seen of him, Durham were slow to accept that Wells would clatter anything short and wide of off stump, as he did when carving Carse over backward point for the four which took him to 50 off 101 balls.

On an afternoon of toil for Durham he accelerated to complete his century off 178 balls by accepting a gift from Rushworth, which he leg glanced for his 13th four.

Van Zyl scored one off his first 26 balls but two whipped pulls for four off successive balls from Carse got him going.

He was fortunate on 27 when a ball from Graham Onions cut back to breach his defence but passed over the stumps. And on 47 he edged the first ball of Onions' third spell between gully and third slip before surviving one of several inside edges, which just missed leg stump.

The score had reached 191 for one when Van Zyl fell for 92, slicing a drive off James Weighell to point, and Laurie Evans made only 19 before becoming Jennings' first victim when he edged behind off the penultimate ball before tea.

With their promotion hopes gone, Sussex handed an opportunity to 21-year-old Phil Salt. But after cracking two lovely fours off Jennings he missed an attempted pull and was lbw.

Jennings' figures read 5-0-22-3, but with ten overs still to go to the new ball he and Weighell came under fire from Luke Wright and Michael Burgess, the deputy for injured captain and wicketkeeper Ben Brown.

They put on 53 before both departed in the first two overs with the new ball, Burgess playing on against Rushworth before Onions nipped one back sharply to take out Wright's off stump.

Ollie Robinson edged Rushworth to Tom Latham at second slip, George Garton turned Onions straight to mid-wicket, and Sam Whittingham inside edged to Richardson, leaving Rushworth with four for 64.