Australia 231 & 333 for 4 (Katich 106, Hussey 67, Watson 65) lead New Zealand 264 by 300 runs
Scorecard and ball-by-ball details

After two days of frenetic activity, Simon Katich returned the game to Test pace and his important, grafting century led to a commanding lead of 300 with six sessions to play. Australia batted poorly in the first innings but Katich virtually eliminated risk during a gutsy 106 that put his side on track for a total of 333 for 4.

The total might already be enough for Australia, who are chasing a 2-0 cleansweep, but Ricky Ponting will be in no rush to declare given there is so much time left and the forecast is for more sunshine. A pitch offering less spin and tricks than expected will also delay the closure and New Zealand will pray for a massive innings to save or level the contest.

There were two periods when the hosts were in with a chance, but once Tim Southee broke through twice in the morning Katich and Michael Hussey crept ahead during a 155-run partnership. Both men fell to Brent Arnel after tea, when the lead was just over 200, before Michael Clarke (42) and Marcus North (42) lifted the pace to power further ahead.

Katich held the innings together over the first two-thirds of the day to ensure there were no terminal wobbles during the most crucial segment of the Test. Australia began the morning with a two-run advantage and Katich really wanted to bat till stumps. He was rarely put off as he played within himself during his 279-ball occupation, which included 12 fours, but when he exited Clarke and North quickly pressed forward.

Clarke was strong off the back foot and he also played some strong drives during an upbeat conclusion, while North, who hit seven fours and a six, was happy to attack Daniel Vettori. It was a bright conclusion to a day in which most of the runs came slowly. After a cautious and considered opening, Katich found his first boundary from his 138th delivery, when he drove an over-pitched offering from Vettori through cover.

Katich brought up his half-century in the over after lunch with a clip behind square off Southee and backed up with another boundary through gully. There were more lulls and then a couple of crashing shots, including two lofted fours over the offspinner Jeetan Patel, while two strong strikes off Chris Martin with the new ball took Katich into the 90s.

A French cut for four off Martin moved him to 99 and the hundred was sealed in the second-last over before tea with a strong cover drive. He allowed himself a satisfied smile for his second century of a consistent summer, which has also contained a string of scores between 79 and 99.

The tea interval disrupted Katich's concentration and he followed Hussey in an almost carbon copy of his dismissal. Both batsmen nibbled at Arnel, who was coming around the wicket, and their fine edges went to Brendon McCullum.

Hussey hasn't had a great series, but he improved with a hard-fought 66 that was committed, purposeful and patient. Like Katich, he wasn't bothered by maidens or mistakes until his nicking curse returned when he had trouble re-starting in the third session.

The spinners operated for large chunks of the day, but neither Vettori, who delivered 33 overs, nor Patel (27) were able to break through despite building regular bouts of pressure. Southee and Arnel were difficult in patches while Martin was looking more like a medium pacer than an attack spearhead.

Southee had Australia 91 for 2 and slowed them down following an 85-run opening stand. The dismissal of Ponting (6) was expertly planned, with Southee delivering a short ball which the captain managed to top-edge pull over the slips for six. Southee's next effort was straighter, trying to get Ponting to hit in the air to the cluttered onside field, and he pushed it hard to BJ Watling at short leg.

The sharp catch followed Southee's revenge on Shane Watson, who hit him for a six and three fours in his first three overs of the morning. Watson (65) became too aggressive again and Southee picked him up to a mistimed pull for the second time in the Test. New Zealand's early-morning breakthroughs and the ones after tea provided some hope of an achievable chase, but Australia regained the ascendancy each time.

Peter English is the Australasia editor of Cricinfo