Lionel Messi, wearing the captain's armband for La Albiceleste as usual, was not only making his 200th appearance in all competitions for his country, but in starting the game, he'd become the first player in history to play at six different World Cup tournaments (Germany 2006, South Africa 2010, Brazil 2014, Russia 2018, Qatar 2022, USA/Mexico/Canada 2026).
Both teams in great form
The two teams had met on just one previous occasion, back in June 2007, when Argentina won a thrilling encounter 4-3.
Algeria came into the match in good form, having not conceded a goal in 393 minutes of play, but they'd need to be at their best to stop Messi and Co., given that Argentina had won all six of their previous fixtures leading into the tournament, scoring 20 goals and conceding just one.
In what is likely to be Messi's last-ever appearance at the finals, too, it was obvious before the game even started that Lionel Scaloni's side were taking their aim of becoming only the third country to retain the trophy seriously.
A sensational start to the match saw two goals disallowed in the opening eight minutes, Fares Chaibi and Messi denied thanks to the assistant's flag.
Messi breaks the deadlock
Though Algeria knocked the ball around confidently, and Aissa Mandi would go on to record a sensational 100 completed passes from 105 attempted (95.2%), it was Argentina who struck first when Messi arrowed a howitzer into the top corner.
A 14th WC goal for La Pulga brought him to within two of Miroslav Klose's all-time record, and was one of four shots the No.10 would have on target in the game (no other player had more than one).
Collectively, Argentina had 68% possession after half an hour of the game had elapsed, with Rayan Ait-Nouri working overtime in the Algerian defence to stem the tide.
Three successful tackles from four attempted would count for nothing in the grand scheme of things, but from a personal perspective, the Man City ace can be satisfied with his output, which also included 11 attempted one-on-ones, the joint-most in the match, six of which were successful, also the joint-most.
Zidane's howler
Unfortunately, his attacking colleagues couldn't match his excellence, and though Chaibi had two more shots at goal just before the break, Algeria still hadn't managed an attempt on target before half-time.
With Enzo Fernandez, Rodrigo De Paul and Alexis Mac Allister winning back possession 19 times between them, Argentina's more robust way of playing was always going to bring further reward, and right on the hour, Mac Allister's fierce drive was spilt by Luca Zidane, with Messi in the right place to side foot home a second goal.
One of his four touches in the opposition box (no one had more) was decisive in that it arguably took the game away from the Desert Warriors at that point.
Algeria's response was to make a triple substitution; however, with De Paul, Mac Allister, Fernandez, Facundo Medina, Gonzalo Montiel, Thiago Almada, Nicolas Otamendi and Messi himself all making at least two successful tackles each, their opponents were left frustrated for long periods.
Messi equals Klose
As the game entered the last 15 minutes, Messi's hat-trick goal crowned a man-of-the-match performance and was his last meaningful contribution as he was subbed shortly after to a standing ovation.
Having equalled Klose's record, he also became the oldest player in WC history (38 years and 358 days) to complete a hat-trick at the tournament.
With Otamendi having taken the armband from his countryman, Argentina didn't need to exert themselves in the closing stages of the match.
Riyad Mahrez's late free-kick straight into the wall summed up Algeria's woes, and they ended the game without a shot on target for the first time at the WC since at least 1965/1966.
Argentina decisive in the big moments
La Albiceleste's collective performance will have served notice on the rest of the countries at the tournament that Argentina mean business, and with Messi in this kind of irresistible form, anything is possible.
They may have been second best in overall possession (47.9% - 52.1%), attempted fewer passes (563 - 608) and significantly fewer dribbles (9 - 24) than Algeria, as well as being less accurate in their collective distribution (89.5% - 91.9%), but what mattered was that Argentina's big players were decisive in the game-changing moments.
Kylian Mbappe and Erling Haaland, both of whom scored braces for France and Norway, respectively, earlier in the day, may yet set the gold standard in terms of goals scored in this tournament, but don't be at all surprised if Messi writes another incredible chapter in his astonishing career.