Marcus North is a smart man. He knows words can suffice only so long before they must be backed by actions. Even the Australian selectors, so reluctant to change a winning team, have their limits. It is not an exaggeration to say that his century at the Basin Reserve was a career saver. How long it will extend his stay in the Test team remains to be seen, but expect to see him at least for the Ashes later this year.

North kept saying he was the man for the job but a slight worry was the presence on tour of Steven Smith, the dazzling allrounder who is everything North is not: young, exhilarating and in wonderful first-class form. Not that it means Smith would be a better Test No.6 than North, but failures in Wellington might have encouraged the selectors to find out next week in Hamilton. Being axed at age 30 is usually permanent.

As North strode to the middle in his languid, lopey style, he realised the seriousness of his situation. This was a man who scraped through the home summer with an average of 23 and then went on to struggle in the Sheffield Shield. From his second ball, which was driven confidently straight down the ground for four, he looked like a different batsman. There was no tentative prodding outside off, nor streaky edges that flew past stumps or slips.

In truth, some of the Sheffield Shield attacks he has faced over the past month might have tested him more than this New Zealand group, which fed him with half-volleys and moved the ball only a little. But an out-of-form North would still have found ways to hit catches or get caught on the crease. Instead, his driving was wonderful, gaps were found regularly and his timing was perfect - in more ways than one.

The innings will ensure that he retains his Cricket Australia contract when the new list is decided in the next couple of months. Had he lost his place in the team, North's deal would have gone south. It remains a concern that North is a fail-or-fire batsman, for whom middling scores are rare. But he was one of Australia's best in the Ashes loss and he is desperate to be there for the next battle for the urn.

"It was a great experience playing in England but there's certainly that motivation to play another Ashes series and make things right," North said. "I guess you never want to be part of a losing Ashes series. Unfortunately my first experience was. But I'll be doing everything I can over the next three Tests to make sure I'm there for the first Test next summer."

Ricky Ponting wants North in his Ashes line-up as well, and has been one of his staunchest supporters. Ponting and Justin Langer have worked hard in the nets with North this week to overcome a slight technical flaw. North found his eyes weren't as level as he thought and fixed the glitch, which he believes has helped him hit straight down the ground. Finding the problem is half the battle, and it significantly boosted his confidence after a tough few months.

"Without doubt the pressure was there and when you haven't made a lot of runs in the last couple of months, there is a lot of speculation about your position," North said. "It's not a great feeling but you have to try and use the experience to motivate and focus on the job at hand. The three days preparation was ideal, it gave me the background to back myself and where my game is and to keep my mindset simple."

When North reached his century with a lucky top-edged boundary from an attempted hook, he jumped and raised the bat, but it was a mostly subdued celebration. There was a casual kiss of the helmet and a slow stroll to his partner Brad Haddin for a handshake, but less of the raw emotion that Michael Clarke had displayed upon scoring his ton.

North can be a hard man to read and rarely looks troubled, but the pressure boiled over earlier in the summer when he swung his bat angrily over his broken stumps after being bowled by Mohammad Aamer at the MCG. This time, the only sign of frustration came when Ponting declared.

North had reached 112, had slog-swept a couple of sixes off Daniel Vettori and wanted to capitalise on his opportunity. Haddin hared off the field to get ready for his keeping duties, while North hung back at the pitch, wishing for a few more overs. At least he ensured he will get a few more matches.

Brydon Coverdale is a staff writer at Cricinfo