Ireland remained on course for a clean sweep of victories from their autumn series by dispatching Australia 21-6 in deteriorating conditions at Lansdowne Road.

Denis Hickie showed his finishing skills for the first of Ireland's two tries, and Geordan Murphy concluded a breath-taking team score which effectively finished the Wallabies.

The tourists played into the strong wind after the interval - and with Ronan O'Gara in magnificent form once again, they could do little to prevent a record-equalling defeat to Ireland.

Skipper Stirling Mortlock landed two penalties but Australia never threatened to score a try and were not helped by having Phil Waugh and substitute Mat Rogers sin-binned simultaneously for fighting.

Ireland, who beat South Africa 32-15 last Saturday, have now clinched back-to-back victories over major southern hemisphere opposition for the first time.

As in the Springboks demolition, Brian O'Driscoll's side were superb in the first half when they scored both tries - and at one point they had strung together 21 phases of possession.

Australia were pulverised up front where man of the match Neil Best spearheaded a dominant forward display and Shane Horgan caught the eye with another dangerous turn.

Fly-half Stephen Larkham was prominent as Australia made an impressive start, charging into the Irish midfield with his first touch of the ball and making considerable ground.

They were able to maintain the pressure when Brian O'Driscoll knocked on close to his line and referee Marius Jonker spotted offside shortly after with Mortlock slotting the penalty.

Australia were playing with the wind, which had picked up significantly, but Mortlock still could not convert a long-range penalty.

Ireland then staged a series of attacks which saw Australia's defensive line stretched to the limit with Matt Giteau making a trysaving tackle on Shane Horgan.

The home side continued to press and appeared to have crossed in the right corner through Murphy after the full-back had rode the tackles of Chris Latham and Wycliff Palu to touch down.

But the television match official, who spent several minutes examining the 'try', refused to award it. Instead, Jonker pointed for a penalty which Ronan O'Gara landed via kind deflection off the uprights.

Australia were under heavy pressure, turning over possession on their own line-out and relying on a last-ditch tackle from Mark Gerrard to keep out O'Driscoll.

Palu was penalised for holding onto the ball after going to ground and Ireland opted for the line-out, even though the penalty was within O'Gara's kicking range.

Their ambition paid dividends as the ensuing move led to a fine score in the left corner - following a juggling display from O'Gara. The Munster fly-half attempted to offload but fumbled the ball and recovered as he went before running out of support.

He spotted Hickie unmarked on the left touchline and fired a crossfield kick which the Leinster winger gathered before jinking between three Wallaby defenders to score.

It was a magnificent finish from Hickie and Australia's problems deepened when Larkham limped off and was replaced by Rogers.

Gerrard kicked the ball out of play, allowing Ireland to stage a fresh assault which Horgan used to offload in the tackle to Denis Leamy — and it took more desperate defending to keep the Munster back row out.

They could not be denied a minute into first-half injury-time, however, as they ran in a stunning try. Superb handling from O'Gara released D'Arcy who dashed forward before feeding Horgan and the big Leinster winger drew Gerrard and supplied the scoring pass to Murphy. O'Gara converted

Australia drew first blood in the second half with a Mortlock penalty but Ireland were still in control thanks to the reams of possession secured by their pack.

O'Gara sent a penalty between the uprights to give Ireland an 18-6 lead and tempers boiled over in the 52nd minute when an exchange of punches between Leamy and Waugh resulted in a large melee.

Both players were yellow carded and Rogers joined them in the sin-bin for involving himself in the fight. Australia's discipline was in danger of disintegrating as Jonker penalised them 10 yards for back chatting.

The Wallabies were seeing more possession but when Ireland came up with the ball in the 58th minute O'Gara sent them deep into opposition territory with a sublime touch finder and then booted his third penalty.

O'Gara missed a 66th minute penalty but Australia looked dead on their feet and seemed incapable of staging a comeback.

Ireland coach Eddie O'Sullivan emptied the substitutes bench but one of the newcomers was quickly back in the dressing room, with Marcus Horan suffering a calf injury.

Little more headway could be made as the conditions grew increasingly worse, but Ireland were already out of sight.