Argentina's Julian Alvarez scored twice and earned a penalty converted by Lionel Messi as they swept past Croatia 3-0 on Tuesday and into the World Cup final where they will face either holders France or Morocco at the weekend.

While all eyes were on Argentina captain Messi and his fifth bid to win the one major trophy eluding him, it was Alvarez who stole the show, earning the penalty and scoring once in each half including after a scintillating 50-meter run.

Messi put away the spot kick in the 34th minute, after Alvarez was brought down by keeper Dominik Livakovic, to become his country's all-time World Cup top scorer with 11 goals.

The 22-year-old Alvarez then took matters into his own hands with his solo effort to make it 2-0 five minutes later.

The pair then combined perfectly in the 69th for Alvarez to tap in his second goal after a mesmerizing Messi drive to the byline and cut-back through the legs of defender Josko Gvardiol to make sure of Argentina's sixth World Cup final appearance.

"Throughout the World Cup it has been incredible what we have lived through and we are going to play the last game which is what we wanted," the 35-year-old Messi said.

"I've been enjoying this for a long time, since we arrived at this World Cup. We asked people to trust us because we know who we are. It's crazy, we did it ... we're going to play another final. Once again, Argentina are in a World Cup final."

Finalists as recently as 2014, the Argentines will look to land a third world crown after 1978 and 1986, even though that looked unlikely a few weeks ago following their opening group defeat by Saudi Arabia that left them facing elimination.

Claiming the world title would elevate seven-time Ballon D'Or winner Messi to the mythical status that the late Diego Maradona enjoys in Argentina.

Sunday they will face either defending champions France or surprise package Morocco, the first Arab country in a World Cup semifinal, who play each other Wednesday.

Croatia, the 2018 runners-up, wanted possession at the start, as they did against Brazil in their quarterfinal, and circulated the ball well but struggled to find a way into the Argentina box.

The South Americans, who have now won every World Cup semifinal they have contested, enjoyed fiery support from their fans who far outnumbered the Croatia supporters in the stands of Lusail stadium, also the site for Sunday's showcase match.

They exploded with a load roar when Alvarez tumbled to earn a penalty after being felled by the onrushing Livakovic.

Messi, who drew level with Germany's Lothar Matthaeus as joint record holder for most World Cup appearances with his 25th game, fired past Livakovic for the lead after Croatia's assistant coach Mario Mandzukic was sent off for dissent.

But the best was yet to come and it was Alvarez, nicknamed 'the spider', who delivered, picking up a Messi pass in his own half, weaving his way into the Croatia box, thanks to two lucky bounces and sloppy defending, before tucking in the second goal.

Livakovic, who had carried Croatia into the last four with saves in their penalty shootout wins against Japan and Brazil, did well to stop an Alexis Mac Allister header on the stroke of halftime that could have killed off the game after 45 minutes.

However, unlike their extra-time comeback heroics against tournament favorites Brazil, there was no way back this time for Croatia.

Argentina were in no mood to squander a two-goal advantage as they did against the Netherlands in the last eight. Alvarez then dashed any lingering Croatia hopes in the 69th, tapping in Messi's cutback to seal the Balkan country's exit.