Pakistan are due to clash with the co-hosts on Friday at the same Adelaide Oval where they knocked the non-Test nation out of the tournament in what was a must-win game.
“Of course we can beat Australia,” Misbah told reporters after the match.
“Nothing is certain in one-day cricket and no one can take victory for granted.
“Obviously Australia will be playing at home and are used to the conditions. They will also get a lot of backing from their supporters.
“But you can never predict what will happen. One good spell or one good innings can change the course of a match. I think any team is beatable, especially in one-day cricket.”
Misbah said the experience of playing two matches at the Adelaide Oval — Pakistan had lost to India in their first match on February 15 — will stand his team in good stead.
“If Australia know Adelaide Oval well, we also have a good idea of what to expect,” he said. “Look, they will be the favourites but all the pressure will be on them. We have nothing to lose.
“We need to bat as well as we did today. Australia has a good bowling attack, so we need to put everything into that game.”
Misbah had already insisted — in the immediate aftermath of the win over Ireland — that there was no reason why Pakistan could not be crowned world champions on March 29.
“Of course we can win the World Cup. We have the momentum. The bowling is doing really well, the batting is beginning to do its part,” said Misbah.
The win over Ireland was set up by Wahab Riaz’s three wickets and two apiece by fellow-seamers Sohail Khan and Rahat Ali that helped to dismiss Ireland for 237 despite skipper William Porterfield’s 107.
Sarfraz Ahmed then scored Pakistan’s first World Cup century since 2007 as the modest target was overhauled in 46.1 overs under lights.
The wicketkeeper returned unbeaten on 101 to emulate Imran Nazir’s 160 against Zimbabwe in Jamaica in 2007, the last hundred hit by a Pakistani batsman in a World Cup.
Pakistan finished third in Pool B behind defending champions India and South Africa, while the West Indies took the fourth place following a six-wicket win over the United Arab Emirates in Napier earlier on Sunday.
Pakistan have now won four games in a row after losing their first two matches against India and the West Indies, and Misbah hoped the team will build on the momentum gained.
“We are not doing anything differently, it’s just that we ran into two good teams who played well on those days,” he said. “But we did not lose heart and the results are there for all to see.”
Misbah said the pressure on Pakistan against Australia will be much less than what it was against Ireland.
“This one we had to win to qualify and everyone expected us to win because we were playing a non-Test nation,” he said. “The boot will on the other foot now.”
Misbah was delighted for Sarfraz, who made an immediate impact on his recall for the last two matches after being left out from the first four games.
“In the practice matches, Sarfraz was not up to the mark and he was not getting runs, so we left him out,” he said.
“But when the batting did not click, we had no choice but to recall him and it has obviously worked well for us.
“I am really happy to see him getting a hundred. I hope he continues the same way in the rest of the tournament.”