Rugby: Now, hopefully, Ireland can at last start to swing from the hip. It's not true to say that Ireland have nothing to lose when they play Australia in their Pool A decider at the Melbourne Telstra Dome today. But they've everything to gain.

Defeat to the hosts and holders, against foes they haven't beaten in Australia since 1979, would not be a disaster in itself. It would depend on how Ireland went down. Were it to come with a big performance, Ireland wouldn't have to budge from their Melbourne base and would have eight days to prepare for a French side that have generated a momentum in this World Cup but also in recent years an agitation about playing Irish teams. And, even in defeat, Ireland would then have a certain momentum of their own.

Were Ireland to win, they would never have had a better chance of obtaining a historic semi-final place. They have proven themselves to be a vastly superior rugby team to either Scotland or Fiji. The re-routing, as pool winners, to a Brisbane quarter-final, would be undertaken with a justifiable swagger.

This is a unique sporting weekend in the Victorian capital of Melbourne. Normally a hotbed of Aussie Rules and racing, today's World Cup clash has been sandwiched by last night's International Rules and Tuesday's Melbourne Cup, attracting an estimated 200,000 sports fans and generating about Aus$50 million.

Even Ireland's threat in the Melbourne Cup is not as pronounced as it was, say, last year, with Dermot Weld unable to mount another raid on the blue riband of Aussie horse racing. And, much to his embarrassment, Willie Mullins's Holy Orders is the talk of Australia, apparently lonely and not inclined to even gallop in training.

However, the Irish rugby squad are certainly not without friends here, and having apparently hummed and hawed, Eddie O'Sullivan has decided that Ireland will not be keeping their powder dry. Support at the 56,347-capacity Telstra Dome might be 50-50. It could be reminiscent of Ireland v Italy in the Giants Stadium in 1994. Ireland were compelled to have a go.

And just being in Melbourne has given Ireland a new-found momentum. Everywhere you look there are replica green jerseys. Even if Ireland were to make the final, they would never have support like this. The Taoiseach has sent his best wishes to the Irish squad for today's game, after last week's meeting with Argentina had "kept us on the edge of our beds". Implicit even in that is the notion that the pressure is now off to an extent.

By comparison, the hosts and holders are under the microscope. Eddie Jones cheekily brought up the spectre of "the spiteful" pool match between the two countries in 1999, notable for Toutai Kefu punching Trevor Brennan's lights out and earning a two-week ban. Of course, Kefu was provoked. Any Australian who has ever stepped out of line was provoked. They run on to the pitch with haloes on their heads.

Jones's comments were interpreted as a sign that the Wallabies were concerned that Ireland were set on "intimidating" his team today. Referee Paddy O'Brien take note. It's standard pre-match Wallabies stuff. But maybe it's a good sign.

It shows Jones is a little worried. Mantra-like, he speaks of the supposedly immense forward challenge presented by Ireland, especially in the scrums. But the Wallabies are masters of negating a genuine scrum contest, and today will probably be no different. Twist it, drop it, bluff and con, confusing scrum and referee alike, and when possible go for a rapid channel one feed.

Most likely, the game will be played to their liking, a multi-phase, rugby league-type contest across the gain line.

There are many misgivings in the Aussie media about Jones's "conservative" selection, especially in midfield where a slimmed-down Matt Burke has been preferred to Stirling Mortlock, but with David Lyons making light of Kefu's absence, Australia look better equipped for the physical collisions and penetrative line breaks which will dictate the flow of this game.

O'Sullivan accepts that Australia are going into this game "fully loaded". Having got their tricky opener against Argentina out of the way, their schedule allowed them to have another run-out against Romania before utilising their squad in the rout of Namibia.

Their frontliners recharged, they have had an additional day's preparation for this game.

"Being the host nation I suppose there was always a chance that things might fall their way," observed O'Sullivan dryly.

Ireland require a huge start, and a key component of that will be the need to be aggressive in their fringe and midfield defence. Australia will go for quick feeds off their scrums and lineouts, and if they get their patterns going, with George Gregan running infield and Stephen Larkham exploring gaps and launching the likes of Wendell Sailor and George Smith back inside, the Wallabies could pull away.

Another concern, voiced by O'Sullivan, is the referee. It's not Paddy O'Brien per se, though Ireland don't have a good track record with him, just that Ireland will be having their fourth Southern Hemisphere referee in four games. And Sunday's 13-8 penalty count against Ireland brought to the coach's mind the 12-6 penalty count against them when O'Brien was in charge of Ireland's 44-5 defeat to France's Grand Slammers of 2002.

"It is a concern, I have to say, in a tight game. These calls make all the difference. I'd be telling a lie if I said I wasn't worried about this aspect of the game," O'Sullivan admitted.

With that also in mind, Ireland, alas, will most probably still lose this game. The pressure, though, will be nothing like last week's, akin to a local derby and a cup tie rolled into one. The key, therefore, is for the team to at least perform.

Although the weather and pressure have been mitigating factors, as O'Gara implied yesterday, they haven't really performed yet. Had they held back even a smidgin mentally today, the cost might have been even greater on the scoreboard, with a heavy defeat leaving them too scarred for a head-to-head with the French, who actually look more complete than Australia at the moment.

It ain't easy to turn on a performance at a week's notice, as if it were on tap.

Head-to-head: Played 22, Australia 11 wins, 1 draw, Ireland 4 wins. Last three meetings: June 2003 - Australia 45 Ireland 16 (Perth); Nov 2002 - Ireland 18 Australia 9 (Dublin); Oct 1999 - Ireland 3 Australia 23 (Dublin, WC). 2003 RWC leading try scorers: Australia - Chris Latham, Mat Rogers 5 each, Matt Giteau, Lote Tuqiri 4 each, Matt Burke 3. Ireland - Denis Hickie, Alan Quinlan 3 each. 2003 RWC leading points scorers: Australia - Mat Rogers 57. Ireland - David Humphreys 23, Ronan O'Gara 22. Betting (Paddy Powers): 1/12 Australia, 28/1 Draw, 6/1 Ireland. Handicap odds (= Ireland + 20pts) 10/11 Australia, 16/1 Draw, 10/11 Ireland. Forecast: Australia to win.

Live scores, commentary from Melbourne on www.ireland.com/sports/rugby/rwc03/