Australia's bowlers have failed to finish off a stubborn Sussex, led by county battler Carl Hopkinson, in their Ashes warm-up match at Hove on Saturday.

Needing to score 418 on the final day to win, the home side was 7-373 when play was called to a halt three overs early after Hopkinson (115) kept Australia at bay with an entertaining century.

Hopkinson, who had only posted one hundred in 55 first class matches, brought up his hundred in the 12-a-side fixture by pulling Marcus North for four before being dismissed shortly afterwards in the final session.

In the end, the Sussex players had to be satisfied with frustrating the tourists and keeping them without a win in the opening match of the Ashes segment of their tour of England.

Ricky Ponting's men now head to Worcester on Saturday night for a four-day match with some selection questions still to be answered before the opening Ashes Test in Cardiff on July 8.

Australian coach Tim Nielsen said he was satisfied with how his team was preparing for Cardiff.

"We can certainly get better but I would rather that we were getting better with another tour game to go then heading into a Test match," he said.

"I am really comfortable with where we are at at the moment, we have not played the longer version of the game for three months."

"All of our batsman apart from Marcus North got some time in the middle so all in all it was a positive week for us."

Nielsen said he wanted to stamp out the high no-ball count with the Australian bowlers being called for overstepping the mark on 38 occasions during the match.

Peter Siddle (1-35) has all but booked the second fast bowling spot alongside Mitchell Johnson with Brett Lee (1-51), Stuart Clark (0-54) and Ben Hilfenhaus (2-70) chasing the guaranteed third pace position.

Spinner Nathan Hauritz (1-60) put in a much improved performance and was better than his figures suggested with Ponting not aiding his cause by putting down an absolute sitter off his bowling.

Hopkinson was dropped on 69 after top-edging a sweep shot that lobbed gently to Ponting at midwicket but the ball popped out of the normally reliable fielder's hands to the delight of locals.

North did his best to shore up his place in the Ashes opener in Wales on Wednesday week by claiming a couple of top order wickets after he had batted at No.6 making just 1 and 11.

Lee earlier struck back in his second spell by having Rory Hamilton-Brown plumb in front after earlier shooting himself in the foot by bowling three no-balls in an otherwise threatening opening spell, including one that cost him a wicket.

His overstepping of the mark will not have impressed coach Tim Nielsen, who warned the problem could cost a bowler an Ashes spot following the 22 no-balls in Sussex's first innings.

Lee stepped over the line as opener Chris Nash (27) appeared to edge a ball to wicketkeeper Brad Haddin.

Siddle ended Nash's blessed existence before Sussex skipper Michael Yardy (67) fell after lunch to North, who had not been used as a bowler during the first innings.

West Australian North then captured Ed Joyce's (34) scalp and Lee removed Hamilton-Brown before Hauritz was finally rewarded when a ball dribbled off Luke Wright (35) and back onto the stumps.

Haddin dropped a touch chance off Hopkinson when he was on 93 from Stuart Clark's bowling before Hilfenhaus returned late in the day to remove the pesky right-hander.

The run rate was always going to be tough to manage and the Tasmanian rattled the pegs of Robin Martin-Jenkins (17) as he chased quick runs.

Andrew Hodd (37no) and Ollie Rayner (4no) remained unbeaten.

AAP