There was no respite for leg-weary Sussex as they were buried under a mountain of runs for the second time in a week.

For Warwickshire last week, read Northamptonshire this. The venue has changed but the Hove wicket is proving to be as benign as the one at Horsham where Warwickshire scored 600.

Sussex managed to remove David Sales in the first hour of the second day before he could inflict too much more damage but wicketkeeper Gerard Brophy piled on the agony with a career-best 181 as Northamptonshire made 570, their highest score against the county.

Ian Ward and Richard Montgomerie replied with a confident stand of 58 in 16 overs, but Sussex lost Ward and the out-of-form Murray Goodwin in the space of three overs and were relieved to negotiate the remaining 22, when only 32 runs were scored, without losing another wicket. They resumed on Day Three on 95-2 with their first target 421 to avoid the follow-on.

Ward had looked in superb form again, but he mis-timed a pull off Steffan Jones and the bowler dived full-length at the end of his follow-through to take a sprawling catch. It is the sort of moment which can inspire a side and Northants struck again when Goodwin prodded tentatively outside off stump at Ben Phillips.

Director of cricket Peter Moores was pleased with the way his bowlers had applied themselves on the first day and he could have had no complaints about their efforts yesterday.

But in the last seven days Sussex have been in the field for 396 overs, the equivalent of nearly four days, and by mid-afternoon it was no surprise that spirits had started to flag.

Despite the flat pitch, a boundary on the scoreboard side of just 65 yards and fast outfield, the scoring rate never got above four an over which says a lot about how well Sussex stuck to their task.

It was good to see Robin Martin-Jenkins, who has not always got the rewards his efforts deserve, pick up the fifth five-wicket haul of his career and first since July 2002.

The fortnight he spent working with Dennis Lillee at the former Australian great's bowling academy in India is increasingly looking like time well spent. No one hit the seam harder and the bounce he managed to extract accounted for two of his three victims.

Sales seemed in the mood to get a move on at the start of the day. He came down the pitch to strike his second ball back over Mushtaq Ahmed's head for six and when he repeated the shot in the leg-spinner's next over, the ball bounced just short of the rope.

But Mushtaq got his man when Sales was hit on the back leg sweeping. His 171 was made in a shade under six hours and included 22 fours and three sixes.

Johann Louw soon popped up a bat-pad catch, but Northants are no different to all of their first division rivals in that they bat very long. Ben Phillips came in at nine to make 73 against Sussex earlier in the month and those with longer memories will recall his record last-wicket stand of 183 at Horsham in 1997 with Steve Marsh during his Kent days.

Here he made 58, helping Brophy put on 132 in 29 overs for the eighth wicket before Matt Prior took a superb one-handed catch at slip off a thick edge.

Tim Ambrose showed similar athleticism to get rid of Jones, but removing Brophy proved an altogether tougher proposition.

He gave one chance when Mushtaq could only get a hand on a powerfully struck straight drive, but was on 165 and probably long past worrying.

He was last out off a top-edged pull, having batted for five hours 25 minutes, faced 242 balls and hit 23 fours and two sixes.