Wallabies thrashed by Michael Cheika's Pumas

The Wallabies have been unable to back up their opening Rugby Championship success, crashing to a 48-17 loss to Argentina in a helter-skelter affair in San Juan.

The Pumas scored seven tries in their biggest-ever win over Australia and, on the back of the thumping bonus-point victory, they moved to the top of the four-nation standings.

Argentina raced to a 26-10 halftime lead with the Wallabies unable to repeat the second half surge that led to their Mendoza Test win last week.

Australia had a James O'Connor try, which would have given them the lead, disallowed in the 20th minute in a baffling refereeing decision and the Pumas scored minutes later in 14-point swing.

It proved a turning point with the remainder of the game almost one-way traffic.

"Massive disappointment," was the assessment by Wallabies coach Dave Rennie.

"We conceded four tries with kicks in behind us and certainly got dominated in the collision area.

"We want to earn the respect of the country and you don't do it with a performance like that."

Pumas coach Michael Cheika switched up his game plan and used their contestable kicking game to expose the inexperience of Australia's back three.

They piled on the pressure in a physical performance with the Wallabies, missing key men such as skipper Michael Hooper through personal leave and injury, bereft of answers.

Australia got off to the worst possible start and they trailed 14-0 after seven minutes.

Veteran winger Juan Imhoff pounced on a mix-up between Wallabies winger Jordan Petaia and fullback Tom Wright and raced to the line before fired-up prop Thomas Gallo barrelled over.

The Wallabies regrouped and got on the board in the 12th minute after Rob Valetini charged ahead and set up a quick pick and go for skipper James Slipper to score, which was soon backed up by an O'Connor penalty for a 14-10 scoreline.

It looked like the visito rs would take the lead after O'Connor crossed after s ome clever interplay with Petaia but referee Karl Dickson and the TMO deemed an earlier clean-out by Slipper was illegal.

It proved a double blow when Argentina centre Jeronimo de la Fuente scored down the other end with Emiliano Boffelli adding the extras for a 21-10 lead.

The Pumas again jumped on some box kick confusion from the visitors with flanker Juan Martin Gonzalez this time gifted the ball to touch down.

The half-time margin could have larger but for a miracle try-saving tackle by Marika Koroibete.

The Wallabies were unable to build into the second half through errors and poor decision-making while the hungry Pumas marched on.

Gallo grabbed his second and then Boffelli crossed before their seventh try by Tomas Albornoz after fulltime capped a memorable match for the home side.

The Australians next face two Tests against South Africa, who split their results with New Zealand.

They will have a number of players availabl e again although Hooper appears unlikely.

While admitted the lack of cohesion hurt his team Rennie said the returning players wouldn't be a quick fix.

"We had a good enough side to do the job ... whoever pulls the jersey on has got to front and we weren't good enough," he said.