Joe Schmidt explains the Wallabies pecking order at 10

Coach Joe Schmidt admits Noah Lolesio's hold on the Wallabies' No.10 has been partly forced by changes around him but he's happy to see the playmaker learn on the job.

Australia pipped Argentina 20-19 in pouring rain in La Plata on Sunday (AEST), Lolesio playing 76 minutes as the Wallabies notched a much-needed Rugby Championship victory to move to 1-2.

The ACT Brumbies five-eighth had halfback Jake Gordon returning inside him and Hamish Stewart debuting at inside centre as a replacement for the injured Hunter Paisami.

Schmidt said those moves meant it would have been problematic to start either Ben Donaldson, who came on for the final five minutes and kicked the match-winning penalty, or Tom Lynagh, ahead of the 24-year-old.

"It's continuity... if you change a 10 as well you start to get a fragmented approach," he said.

"We wanted to keep some continuity and grow the confidence that Noah is starting to build."

Stewart was the Wallabies' 15th debutant this year, the most they have blooded in a calendar year since 1962. 

"There's not a lot of room to breath," said Schmidt.

"That's a whole team of debutants and we're trying to build continuity and build some depth."

The Wallabies scored just one try across two losses to South Africa to begin their Rugby Championship campaign and battled again for fluency in ghastly conditions on Sunday (AEST).

In the opening minutes the Wallabies held the ball for 27 phases, but went backwards before Lolesio's grubber kick was easily picked off.

He also missed a penalty kick on the stroke of halftime and then threw a loose pass to an isolated Nick Frost that cost the Wallabies the lead in a momentum-shifting moment they were able to overcome.

But he also nailed another, tougher penalty kick and would have created the match-winning try had Max Jorgensen hung onto a pass after Lolesio sprinted clear from broken play.

Outside centre Len Ikitau and fullback Tom Wright provided much of the offensive spark behind good work from Australia's forwards but coach Joe Schmidt still reserved praise for his playmaker. 

"I love the way he backed himself ... ran out from his own 22 and almost set up Max Jorgensen for what would have been a fantastic try," he said.

"Forced a ball to Nick Frost when I think he would have been better off going downtown (with a kick).

"It's easy for people in a box with a full view to make those decisions but he's in a swirly, wet, hostile arena and I thought he managed himself really well.

"There's always things that he'll pick apart and he's challenging himself more and more and I like that."

With Gordon among the Wallabies' best, Schmidt will weigh up his selection options for a rematch in Santa Fe this weekend. 

Emerging forward Isaac Kailea suffered a head knock in the second half and has been sent home to complete return-to-play concussion protocols.

Queensland Reds prop Zane Nonggorr will join the squad in his absence.