Match ends, Argentina 0, Croatia 3.
Argentina are facing the prospect of an early World Cup exit after a dreadful error from goalkeeper Willy Caballero set Croatia on their way to victory and a place in the last 16.
On a night when so much was expected of Argentina captain Lionel Messi, Caballero made the most telling contribution to his team's fate with an attempted chip over Ante Rebic that backfired badly, allowing the striker to volley into an exposed net in the 53rd minute.
Messi - adrift for much of the match, especially during a pedestrian opening half - rallied his side, but neither he nor substitute forwards Gonzalo Higuain and Pablo Dybala could find a way through in Nizhny Novgorod.
The closest Messi came was a half-chance, a snatch at a rebound from a Maximiliano Meza shot which was blocked by Ivan Rakitic and turned behind to safety.
- Is the pressure too much for Messi & Argentina?
- How did you rate Modric & Messi?
- Reality of squad clouds Messi's brilliance - coach Sampaoli
- World Cup Daily podcast: 'Pure Argentine anger' with Zabaleta
It was a dogged defensive second-half display from Croatia, illuminated by a moment of magic from their own masterful number 10, Luka Modric.
His curled shot from range drifted beautifully beyond Caballero's dive to put his side two ahead, before Rakitic's injury-time tap-in sealed a victory that moves the Europeans through to the knockout stage and also leaves them in a strong position to win the group.
Argentina are no longer in control of their own destiny. This defeat follows their opening 1-1 draw with Iceland, in which Messi missed a penalty, and now even a heavy win over Nigeria in their final game on Tuesday may not be enough to send them through to the next round.
Should Iceland beat Nigeria in their second Group D game on Friday, Iceland would need only a draw against Croatia in their final match.
For Messi, a prolific performer at club level with Barcelona, this was another harrowing chapter in his recent history of pain and disappointment in the international game.
Carrying the expectations of a nation
As the national anthem was played before the match, the camera panned across Messi's face. Eyes closed as he rubbed his forehead, he looked like a man carrying the expectations of a nation.
He wanted to perform too, to carry his team in the shape of his own greatness like the legacy of Diego Maradona says he must, but this was a long way from a classic Messi display. This is also a long way from a classic Argentina team.
In the first half they were easily exposed on the flanks, conceding three first-half chances behind the full-backs which a more ruthless side than Croatia would have punished.
At the other end, Enzo Perez missed a sitter and looked out of depth in midfield, while Messi was often wandering in empty space with the game played somewhere else.
It was a strange thing to watch, to see the player who is so often nothing less than masterful at the highest level of the club game not stepping forward into the spotlight.
There seems to be real tension - a barrier almost - to success in the blue and white stripes of Argentina.
It has become more pronounced and painful over the past four years, during which Argentina lost three major finals with Messi as captain.
After the most recent of these - defeat by Chile in the 2016 Copa America - Messi announced his international retirement, having missed a penalty in the shootout.
He reversed the decision a month later but now, three days before he turns 31, you feel this really was the last big chance he had of propelling his side to victory on the biggest stage of all.
Even if international success does not come - and it looks a long way off - he will still be the player who has achieved so much and seduced so many in 14 years at Barcelona.
But at a tournament where Cristiano Ronaldo is again dragging Portugal along with his goals and drive, there will forever be regret and a sadness that a player as talented as Messi looks likely to have one thing missing: a World Cup he defined.
Croatia wasteful before Caballero nightmare
Until Argentina crumbled late on, Croatia had not been particularly impressive either.
Although they probably edged the quality of chances created, they were all chances wasted. Ivan Perisic had a low drive brilliantly tipped round the post, Mario Mandzukic put a low header wide from six yards, and Rebic blazed wastefully over from a wondrous Modric through ball.
There were few signs to suggest Croatia would end up winning as convincingly as they did as Argentina enjoyed the majority of possession and almost scored a freakish opener when Meza hit the top of the bar with a cross.
Later, Croatia produced moments of real quality such as Modric's sumptuous curled finish and the composed passing before Rakitic's third. But those came after the defining action of the night - Caballero's mistake.
He is only covering Manchester United's Sergio Romero, who was ruled out before the tournament through injury.
It was the kind of error nightmares are made of, and it seemed to strike a blow at the heart of the morale of the Argentina team.
So many heads, including Messi's, dropped in bemusement and misery. From that point on, it only got worse for them.
Man of the match - Luka Modric (Croatia)
'I beg for forgiveness' - reaction
Argentina coach Jorge Sampaoli: "First and foremost I beg for the fans' forgiveness. The reality of the Argentina squad clouds Lionel Messi's brillance. The team doesn't gel as well as it should.
"I have always looked for the best position on the pitch for my players. The players have a special responsibility as well, but we didn't manage to find relationships that Argentina or Lionel Messi benefited from.
"Croatia were an excellent team, but after we conceded we lost our way and we were emotionally broken. We couldn't change the course of events.
"I am very hurt by the defeat but I probably didn't understand the match as I should have."
Croatia coach Zlatko Dalic: "I have trusted my team from the first day. I didn't believe we would be through after the second game so we have to be happy because we have beaten a strong Argentinian side with the best player in the world. Argentina were not confused; we were excellent.
"Over the last few days we haven't looked at tactics because I wanted to relieve my players of the stress. We had good scouts and we analysed the opposition well. We adapted our style to them. Let's enjoy this moment.
"In the first half we were compact and created three sitters but we failed to score. That's why I told the players in the second half that we will create more chances but we had to press higher."
Argentina's worst run without a win - the stats
- This was Croatia's first victory in five attempts against a South American team at the World Cup, having lost the previous four.
- This was Argentina's heaviest defeat in the first-round group stage of a World Cup since losing 6-1 to Czechoslovakia in 1958.
- Argentina have failed to win either of their opening two group stage matches for the first time since 1974.
- This was Croatia's joint second biggest World Cup victory; they beat Cameroon 4-0 in 2014 and Germany 3-0 in 1998.
- Argentina are without a win in their past four World Cup games (D2 L2), their longest such run in the competition.
- This is only the second time Croatia have won their opening two games at a World Cup, after the 1998 tournament that saw them reach the semi-finals.
- Ante Rebic's goal was his second for Croatia, and his first since August 2013 in a friendly against Liechtenstein.
- Two of Luka Modric's four goals in major tournaments for Croatia (Euros and World Cup) have been from outside the box.
- Argentina's Lionel Messi, who had 11 shots in the opening game against Iceland, did not manage a single attempt in goal until the 64th minute.
- Messi has had more shots than any other player at this World Cup (12) but has failed to score with any of them.
- 2MercadoBooked at 51mins
- 17OtamendiBooked at 85mins
- 18SalvioSubstituted forPavónat 56'minutes
- 15PérezSubstituted forDybalaat 68'minutes
- 8AcuñaBooked at 87mins
- 19AgüeroSubstituted forHiguaínat 54'minutes
- 11Di María
- 20Lo Celso
- 2VrsaljkoBooked at 67mins
- 18RebicBooked at 39minsSubstituted forKramaricat 57'minutes
- 4PerisicSubstituted forKovacicat 82'minutes
- 17MandzukicBooked at 58minsSubstituted forCorlukaat 90+2'minutesBooked at 90mins
- 12L Kalinic
- Ravshan Irmatov
- Shots on Target
Second Half ends, Argentina 0, Croatia 3.
Foul by Nicolás Tagliafico (Argentina).
Danijel Subasic (Croatia) wins a free kick in the defensive half.
Vedran Corluka (Croatia) is shown the yellow card for a bad foul.
Lionel Messi (Argentina) wins a free kick in the attacking half.
Foul by Vedran Corluka (Croatia).
Substitution, Croatia. Vedran Corluka replaces Mario Mandzukic.
Goal! Argentina 0, Croatia 3. Ivan Rakitic (Croatia) right footed shot from the centre of the box to the bottom left corner. Assisted by Mateo Kovacic following a fast break.
Attempt saved. Ivan Rakitic (Croatia) right footed shot from outside the box is saved in the bottom left corner. Assisted by Andrej Kramaric.
Corner, Argentina. Conceded by Domagoj Vida.
Attempt blocked. Maximiliano Meza (Argentina) left footed shot from the centre of the box is blocked. Assisted by Lionel Messi.
Attempt missed. Luka Modric (Croatia) right footed shot from outside the box misses to the left.
Attempt blocked. Mario Mandzukic (Croatia) left footed shot from outside the box is blocked. Assisted by Mateo Kovacic.
Foul by Nicolás Tagliafico (Argentina).
Mario Mandzukic (Croatia) wins a free kick on the right wing.
Marcos Acuña (Argentina) is shown the yellow card for a bad foul.
Foul by Marcos Acuña (Argentina).
Sime Vrsaljko (Croatia) wins a free kick in the defensive half.
Attempt missed. Mateo Kovacic (Croatia) header from the centre of the box is high and wide to the left following a set piece situation.