It is a sight every goalkeeper in the world fears, and the vast majority have ultimately failed to deal with: Lionel Messi bearing down on your goal, ready to distil all that talent into one decisive moment.
For Asmir Begovic, it was an assault on the senses as much as his goal. "You can feel the pace of his play, the power he has. We tried to get two or three people around him every time he got the ball, but he shook everyone off."
That goal against Bosnia and Herzegovina, which sealed a 2-1 victory for Argentina in their opening game, ignited Messi's World Cup campaign. Since then, he has completely banished so many pre-tournament debates about his World Cup legacy, while consistently breaking supposedly psychological barriers and reaching new landmarks.
On Saturday, another significant block presents itself, and it is a literal one that may yet prevent Argentina from reaching the World Cup semifinals for the first time since 1990. It also represents something of an inversion of all the old debate surrounding his international career, since it is one area he has struggled with in club football.
That is the daunting physical presence of Thibaut Courtois. Messi has not scored against the Atletico Madrid goalkeeper since December 2012, a drought that has now extended to seven games. Those seven matches also played a major part in ensuring the Barcelona creator last season suffered the first trophy-less campaign of his career since 2007-08.
Now, in goal for Belgium, Courtois is the most immediate obstacle to Messi getting his hands on the trophy he desires above all else. To complete his legacy with the World Cup itself, the 27-year-old is likely going to have finish past the Belgian.
"I know very well how to play against Messi," Courtois said this week. "We have come up against each other in various games between Atletico and Barcelona, although on those occasions the defeats were not his fault. Messi is a sensational player. He can decide a game in a second."
Courtois has accumulated many minutes against Messi, which has meant he doesn't have to prepare in the usual way. That wouldn't exactly help anyway, however, since Messi is not a usual player. "The good thing is I don't have to watch videos of him because I know him so well," Courtois explained. "But, even if you watch videos of him, he's so unpredictable that it's impossible to study him to know what he's going to do. As soon as he finds a way to shoot, he will shoot, so the only thing you can do as a goalkeeper is concentrate at all times."
The duel has already taken on other dimensions, given that it was Belgium that Argentina met on the way to the 1986 World Cup and saw Diego Maradona score another of those iconic goals. In truth, however, there also other dimensions to this battle right now. It is obviously much more than a mere mental block as Courtois indicated by saying it isn't all Messi's fault, effectively admitting it isn't all down to his goalkeeping.
Most obviously, there was the defensive system set up by Diego Simeone at Atletico. It was widely praised in each of those seven games, generally seen as the primary reason for preventing Messi scoring. It wasn't quite that the No. 10 couldn't beat Courtois; it was that he couldn't get near enough to really try. Simeone's four-man blockade didn't allow Messi to work himself into those positions for his most productive shooting.
You only have to look at the stats. In seven games, Messi had 16 shots, but only three were on target. As such, it wasn't really Courtois miraculously keeping out a siege. He may have to on Saturday, however, if Belgium don't set up a similar blockade.
"It will be tough," Courtois said. "To hold on in defence, we must be very well-organised." This is perhaps the true intrigue to this quarterfinal: how both teams set up.
Belgium finally looked liberated against the USA and possess the pace on the break to finally hurt Argentina. Courtois also referenced this. "Argentina have a very good attack, which does not just depend on Messi," the goalkeeper said, "but at the back they are not so strong. That is where we can do them damage."
At the same time, surging forward in itself may be damaging for Belgium. Although Argentina have not been firing in attack, it might ignite them if a team suddenly offers up the space so often obstructed. That has been one primary reason Alejandro Sabella's side have not looked their best. None of the four teams they have played -- Bosnia-Herzegovina, Iran, Nigeria and Switzerland -- have been willing to step up. So Belgian manager Marc Wilmots has a decision to make.
One thing is certain: given Messi's form, Wilmots absolutely must replicate Switzerland and Atletico in forming some kind of tactic to shuttle the playmaker out of the game. Thereafter, it will be revealing to see whether Sabella goes so gung ho in response. Given Belgium's own attack, the Argentina coach may seek to revert to the 5-3-2 used by Bosnia and Herzegovina that initially so isolated Messi.
It would be ironic, yet it could also be the key to ending another trend, and offering a new sight: Messi finally finishing past Courtois in a match that really matters.