Australia’s fitness and ruthless work at the breakdown have been identified by Wales as key elements in their pivotal Rugby World Cup group D showdown.

Both teams opened their campaigns with imperfect wins over capable opposition, setting up the clash at Tokyo Stadium as a likely group decider.

At stake is a potentially easier quarter-final fixture.

If things play out as expected in group C, Sunday’s winner will probably meet France in the first knockout round while the losers would encounter a power-packed England.

Wales spluttered in the second half of their 43-14 defeat of Georgia on Monday while Australia operated in reverse order, finding their feet after half-time to see off Fiji 39-21.

Welsh winger and tryscorer Josh Adams was among their best, particularly in the first half as they strung together some spectacular tries to lead 29-0 at the break.

Sharing the second half spoils 14-14 was disappointing, Adams said, and a concern given how strongly the Wallabies had finished.

“Australia looked fast and fit last weekend and in the latter stages of the second half they really put their foot on the throat to rack up their points,” he told journalists.

“Looking at it, you could argue it is the crunch game but we have to dust ourselves off first of all.”

When nominating key players in the opposition ranks, Adams pointed to in-form speedster Marika Koroibete, who will play on the opposite wing, and the twin breakdown strike weapons of flankers Michael Hooper and David Pocock.

“In the second half of the Georgia game we were a bit weak over the ball and got pushed off a couple of times. That is going to be a big emphasis for us with Pocock and Hooper, so we need to tighten up that contact area,” he said.

“Turnover rate is quite important. We can’t give teams as good as Australia easy ‘ins’ into our half.”