Australia was given a taste of life without Glenn McGrath as New Zealand briefly took control of the third and deciding cricket Test at the WACA here today.

With opener Lou Vincent joining an elite band of players by scoring a century on debut and captain Stephen Fleming ending years of self-doubt by scoring his first century in 42 months - Australia was on the ropes for much of the day.

New Zealand finished at 7-293 with the match evenly poised.

It's no coincidence that New Zealand's ascendancy corresponded with McGrath's absence.

The tall fast bowler, who has played 41 consecutive Tests, was out of the attack for a total of four hours today when he suffered back spasms after bowling five overs.

When he left the field to go to hospital for precautionary scans, New Zealand was 2-19 and hovering on the brink of another batting slump.

When he returned to the attack late in the day, the Black Caps were 3-226 after Vincent (104) and Fleming (105) added 199 for the third wicket.

With Steve Waugh having to manage his bowling assets, the Kiwis had the luxury of 10 overs from Damien Martyn, Mark Waugh and Ricky Ponting while Shane Warne bowled much more than he would have anticipated on the first day of a WACA Test.

Just enough pressure was taken off for the New Zealanders to flourish.

The tourists were also helped by cool, overcast and windy conditions and a pitch which lost some of its bite as the sun went off it.

"It was a pretty flat wicket - an ideal wicket to play cricket on," Vincent said.

As soon as McGrath took the ball again, things went downhill for the Kiwis.

While he didn't take any of the four wickets to fall late in the day, his presence alone appeared to lift the Australians who had drifted through the middle session.

New Zealand slumped from 3-264 to 7-281 as Brett Lee (2-89) and Jason Gillespie (3-79) did the damage with the second new ball.

Vincent admitted "things looked good for a while" when McGrath was away.

"It's mixed emotions towards the end there I was hoping we'd finish a maximum five down - seven down's a bit of a kick in the guts," Vincent said.

New Zealand skipper Fleming preferred not to talk about his own century saying "it's Lou's day".

And it was Vincent's day - from the moment he was beaten all ends up by the first ball he faced from McGrath.

"I played and missed but I didn't nick it - so I thought it could be my day," he said.

He praised Fleming for getting him through the day to become the sixth New Zealander to make a century on debut.

"He's an inspiring leader, he kept me cool and composed at times in the game when the timing, the head and the feet were all over the place."

The 23-year-old Vincent had never opened the batting in a first-class game before today but the Kiwis gambled on his raw potential and positive attitude as they sought to become the first side in nine years to win a series in Australia.

That is still a possibility but Fleming said the way Australia roared back in to the contest was a warning for his team.

"It was a very impressive the way they came back but at seven for 293 we're still in the game and we'll be looking to make 350-plus tomorrow."

Gillespie removed Craig McMillan (4) and nightwatchman Daniel Vettori (2) before Lee sent dangerman Chris Cairns (8) back to the pavilion.

At stumps, Nathan Astle was on 28 and Adam Parore on five.

While Fleming played down his effort, even the Australians stopped to applaud his century.

It's been three and half years and 48 innings since Fleming made his last century - against Sri Lanka in May 1998.

In his 63rd Test it was just his third century - although he passes 50 every second match he plays - and his first against Australia.

© 2001 AAP