Brian O'Driscoll and Ireland lost 37-15 to Australia

"All three Tests were particularly hard as we knew they would be and they took their toll," said O'Driscoll, whose team also lost twice to New Zealand.

"I think the legs started to get heavy after three weeks of Test rugby.

"We felt we had an opportunity to come down and claim a scalp but it shows we have some way to go yet."

Australian captain George Gregan said it was no surprise they had to wait until the fourth quarter to get well on top.

"We knew Ireland would compete hard and that we would have to be patient," said the try-scoring scrum-half.

"We expected Ireland to throw caution to the wind in their last game.

"They came out in the second half and caught us on the hop a little but we reassessed, kept our heads, and got back in it."