When it comes to spin bowling Sussex are not just about Mushtaq Ahmed as Mark Davis reminded everyone at Wantage Road.

On a ground where the twirlers have prospered for several years it was no surprise that Mushtaq was soon among the wickets on the first day against Northamptonshire.

Mushy would agree that he was outbowled by his team-mate, who took three wickets in an innings for only the second time since 2002 on his first four-day appearance of the season.

When Davis removed Gerard Brophy and Johann Louw with successive deliveries midway through the afternoon session, Northants were in the mire at 186-7 on a flat pitch which should have held few terrors.

They were revived by a maiden hundred for his new county from Usman Afzaal and by Ben Phillips, a player Sussex tried to sign a few years ago. They had put on 108 in 30 overs when bad light ended play 35 minutes early.

Sussex bowled with good discipline considering so little was happening for them. After spending most of the last two weeks watching the rain fall, the bowlers were grateful just to get some overs under their belt, none more so than Davis.

His most important contribution to last season's Championship success came with his career-best 168 which turned the Middlesex match.

While Mushtaq was becoming the first bowler to take a hundred Championship wickets for five years, Davis's 14 first-class victims cost him more than 50 runs a piece.

He does not give the ball a big rip, but his control of line and length is normally good and when he tosses the ball up, he is capable of luring a batsman into a mistake.

Just ask Graeme Swann who led a spirited counter-attack after Mushtaq and Jason Lewry had shared the first four wickets.

Lewry removed openers Tim Roberts and Mark Powell in a new ball spell and Mushtaq was brought on within the hour.

His 11 overs before lunch cost 24 runs and brought the wickets of Martin van Jaarsveld, who was deceived by a top-spinner, and David Sales who missed a straight one in the sixth over after the interval to leave Northants in trouble at 90-4.

Swann refused to be shackled. He took 18 off one Mushtaq over, twice hitting him over long on and then clearing the mid-wicket boundary as he raced to his third fifty in a week off just 38 balls with five fours to boot.

Mushtaq was removed from the firing line after conceding 56 in nine overs after lunch, but Chris Adams' gamble in replacing him with another spinner soon paid off. In his second over Davis tossed one up and Swann sliced a drive to backward point.

It got better for Davis in the fifth over of his spell. Brophy gave a return catch off a leading edge as he tried to work the ball through square and Louw immediately missed a straight one. Phillips averted the hat-trick and soon got his head down to give Afzaal the support he deserved.

Afzaal was scoring a Test half-century against the Australians three years ago, but in his final season at Trent Bridge he scored just 264 Championship runs and his career appeared to be in freefall.

A change of county seems to have invigorated the left-hander. A slow pitch inhibited his natural instinct for attacking strokeplay so there was a lot to admire in his disciplined approach and no disguising his delight when he completed his hundred after five-and-a-half hours, having hit 12 boundaries.

He had two escapes. On 43, Murray Goodwin could not hold on to a fiercely struck cut at gully while a heavy-legged Mohammad Akram did not get close to a miscued drive at mid on when he had made 82.