Despite losing their first match in one of the great World Cup upsets against Saudi Arabia, the two-time former winners still bounced back to win Group C and now face a favourable last-16 draw against outsiders Australia.

It was a dramatic turnaround for one of the pre-tournament favourites following the doom and gloom that met their opening result.

"I think we're back to being the team we used to be" before the Saudi loss, said goalscorer, Alexis Mac Allister, following Wednesday's 2-0 win over Poland.

But had Argentina ever really stopped being themselves? Argentina came into the World Cup on a 36-match winning run and was on the brink of equalling the unbeaten world record.

But after a fast start against the Saudis in which Messi gave them a 10th-minute lead from the penalty spot, their fortunes quickly unravelled.

Three times in the first half they had the ball in the net only to see an offside call go against them. Then two goals in five minutes at the start of the second half took their legs out from under them.

Suddenly, Argentina was facing the very real prospect of crashing out in the group stages. And even though they won their next two matches 2-0 against Mexico and Poland, it was not always convincing.

Never worried

Argentina looked clueless in the first half against Mexico, unable to break down the low defensive line with a back five.

It was only after Messi found space and fired in brilliantly from just outside the box that the Albiceleste started to exert their authority.

And while they dominated from start to finish against Poland, Messi did miss a first-half penalty, meaning they reached halftime with the nervy game still goalless.

It might seem that Argentina squeaked through and many questioned following their Saudi defeat whether the South American giants' prowess had been overestimated.

But if truth be told, they have only lost once in 39 matches and barring that crazy five minutes at the start of the second half against Saudi Arabia, they have hardly experienced a worrying moment at their end of the pitch in Qatar.

Coach Lionel Scaloni was certainly never worried.

"We'll pick ourselves up and win the (next) two games," Scaloni said after the Saudi defeat, a match he insisted they deserved to win.

"In the first half we played well and could have gone 2-0 up, but in two instants the game changed." Only a marginal automated offside call denied Argentina the second goal against the Saudis in a half they had totally dominated.

They were well on top against Mexico and should have beaten Poland by a far wider margin.

Team clicking

In Messi, they still have one of the greatest players in the game. Despite his missed penalty, he has been a key figure for Argentina.

He caused havoc in the Polish defence with several purposeful dribbles and it was he who gave Argentina the lead in their first two matches.

The rest of the team now seems to be clicking and they have a wealth of options to bring off the bench.

Talented pair Lautaro Martinez and Angel Di Maria started the first two games alongside Messi in attack, but young Manchester City forward Julian Alvarez scored from his start against Poland.

Precocious Benfica talent Enzo Fernandez made a goalscoring entrance off the bench against Mexico with a contender for the goal of the tournament.

He then celebrated his first start for his country by setting up Alvarez against Poland. Two clean sheets attest to their defensive solidity while Rodrigo De Paul in midfield has improved with every match, gradually asserting ever more authority.

Argentina barely allowed the Poles a kick, their suffocating press often winning back the ball high up the pitch and quickly after losing it.

Polish goalkeeper Wojciech Szczesny was their best player.

Some people said the real Argentina finally stood up against Poland, but they are not about to get complacent, even against a team 35 places below them in the FIFA rankings.