Australia coach Joe Schmidt was left "massively relieved" after his team rescued a 21-18 win over Fiji thanks to Harry Wilson's late try.

Wallabies captain Wilson went over with just a minute left on the clock at McDonald Jones Stadium on Sunday.

Wilson's score denied Fiji a famous win over the Wallabies, who they also beat at the 2023 World Cup.

Australia's performance, though, left Schmidt knowing there is plenty of work to do ahead of the Wallabies facing the British and Irish Lions in a three-Test series that begins on July 19.

"Massively relieved, because you want to get a result," Schmidt said.

"But I am disappointed with the performance and I know the players will be looking for more out of themselves, and that has to happen in a very short space of time.

"Thirteen days' time, we won't be afforded the number of errors that Fiji gave us.

"Fiji were superb. Some of the players we knew would be elusive and quick and powerful, and they turned up and were all those things."

Fiji were hunting their first win on Australian soil in over 70 years, and were on course to get it when they fought back from 14-5 down to lead 18-15.

Dave Porecki and Fraser McReight put Australia ahead, but Fiji debutant Salesi Rayasi reduced the arrears.

Lekima Tagitagivalu crossed and Caleb Muntz converted two penalties to put Fiji ahead, yet Wilson came up with the goods for the Wallabies in the closing stages.

"Some of it was frustration and some of it was relief to find ourselves in that situation after we built a nice lead early in the game," Schmidt added.

"I felt we got a bit loose and they've got some fantastic broken field runners but that was no surprise to us because we knew they had them and we knew we'd have to be better connected than we were.

"It was certainly a relief when Harry got over and dotted it down. 

"We missed a few opportunities to really put scoreboard pressure on them. We've got to iron those out to be super accurate because if you don't nail your opportunities, you don't get to build their scoreboard pressure and as long as they believe there's a way for them because they're so athletic.

"We didn't play well enough for people to have the expectation that we're going to come bowling into Brisbane and knock the Lions over. I'm not sure that expectation was there before today.

"We're just going to have to build that quiet resolve that inch by inch we can work our way toward that."