Australia-born Mack Hansen's hat-trick of tries inside half an hour of the first-half inspired Ireland to a 46-19 victory over Australia at Lansdowne Road on Saturday in their Autumn Nations Series Test.

The Irish set themselves up perfectly for the daunting clash with world champions South Africa next Saturday by posting a record win for them over the Wallabies.

Hansen, who recently returned from a foot injury, played down his personal achievement.

"That is the pleasure of playing with this team, I just had to grab the ball and run over the line -- I didn't really have to do much!" he said.

"There has been a lot of talk that I wasn't born here and didn't grow up here, but this feels like home."

Ireland head coach Andy Farrell was delighted that his side had been sharper after below-par performances against New Zealand and Japan.

"To keep playing to the to the end and play some good stuff right until the bell shows some nice character from ourselves," he said.

"It wasn't all going our way, but we found a way to compose ourselves.

"I think it was very pleasing in the second half how we managed the game."

Australia head coach and former Ireland handler Joe Schmidt was disappointed at how the game slipped away from them in the final 20 minutes.

"Tough one to take," Schmidt told Stan Sport.

"They conceded a lot of penalties in that first half... and we felt that if we could keep squeezing them, but I think they had about 70 percent possession in the second half.

"The synchronisation just wasn't there."

- Prendergast class -

It was the second successive week that Schmidt's side had been undone by one of their own as Australia-born Monty Ioane and Louis Lynagh, who was born in Italy but is the son of Wallaby legend Michael, had scored tries for Italy in their win over the Wallabies.

The Irish bolted out of the blocks.

Hansen, playing at fullback for the first time at Test level, touched down under the posts twice inside the first quarter of an hour.

Sam Prendergast converted both for 14-0.

However, Prendergast came off second best shortly afterwards as Len Ikitau barged through him to score.

James O'Connor converted for 14-7.

Prendergast's ability to do the unexpected is what head coach Andy Farrell likes about him and the 22-year-old delivered as the clock ticked towards 30 minutes.

His crossfield kick to Tommy O'Brien was perfect and although the wing was brought to ground, 27-year-old Hansen was in the right place to pick the ball up and cross the line.

Australia, though, were right back in it at half-time.

Flanker Fraser McReight bundled over after a period of persistent pressure -- O'Connor added the extras to leave them just 19-14 down at the break.

- Harry Potter magic --

Australian wing Harry Potter produced some magic in defence when he held up Irish hooker Dan Sheahan on the tryline as the hosts pressed in the early part of the second-half.

Prendergast gave the Irish breathing space with a fabulous long range drop goal for 22-14 with 25 minutes remaining.

He went off soon afterwards and his replacement, Jack Crowley made an instant impact, converting a penalty for 25-14 with under 20 minutes remaining.

The hosts dashed any outside hopes the Wallabies had of coming back when the irrepressible Hansen's catch inside the Aussie 22 led eventually to captain Caelan Doris touching down.

Though the visitors were reduced to 14 men with Nick Frost sin-binned, they showed great spirit as Billy Pollard went over for 32-19.

However, the Irish were to have the last laugh as Ryan Baird and then Robbie Henshaw went over -- Crowley converting both -- to round off a hugely satisfying night for the hosts.