The final round-of-16 match takes place on Tuesday as the much-touted Belgium team takes on one of the tournament's surprise packages when they face USA.
Belgium qualified as winners of Group H, making comfortable work of seeing off Russia, Algeria and South Korea.
USA came through a final group game defeat against Germany but still qualified in second position in Group G, ahead of Cristiano Ronaldo's Portugal.
Here is how you can watch the exciting knockout fixture.
When: Tuesday, July 1, at 9 p.m. BST (4 p.m. ET)
Where: Salvador, Brazil
TV: BBC HD (UK only); ESPN (U.S. only)
The Redemption of Marouane Fellaini
The misery has been clear on the face of Marouane Fellaini for many months after his ill-fated transfer to Manchester United from Everton.
The big midfielder, who had been such a hit in front of goal in the Premier League for an extended time, was reduced to a bit-part role as United crashed and burned under David Moyes.
But on the international stage, Fellaini has more fans than critics, and he proved his worth in Belgium's first match of the competition. The player scored the vital equalising goal for his country as they overcame a resilient Algerian side with defeat on the cards.
Since that match, where Fellaini started on the bench, the United player has started the rest of the group games and Belgium have not conceded a goal.
The 26-year-old has formed a very tidy partnership with Axel Witsel in the heart of Belgium's midfield, and they have looked solid and sturdy.
Belgium coach Marc Wilmots expects a physical battle with the USA and will need Fellaini and his partner to be at their best. Wilmots said, per BBC Sport:
"Physically they [USA] are very strong. We are preparing for a war."
Midfielder Kevin de Bruyne added, per BBC Sport:
"We cannot compare this game to the friendly last year [where Belgium beat USA 4-2]. Besides we are playing a knockout match which is completely different."
USA have shown they no longer reside in the bottom tier of international football and, despite not having the star names that Belgium possess, they will be a tough match for the European team.
Belgium have yet to be truly challenged at this World Cup, despite Algeria's efforts in the first match, and it will be interesting how they will cope with a bombastic USA side.
Fellaini will start for the Red Devils, which will prove a test as to whether he will return to Manchester as a hero or an also-ran.
USA Ready for the Biggest Game of Their Lives
USMNT start the match against Belgium as second-favourites to qualify for the quarter-finals, but it will not stop them giving their hearts and souls to progress to the next round, in what would be their nation's greatest soccer victory.
Pound-for-pound the fight is a mismatch, with a heavyweight puncher up against a middleweight contender. But the USA have a dangerous weapon in the form of Clint Dempsey, who has accrued many years of Premier League experience and taken many a scalp.
USA and Everton goalkeeper Tim Howard spoke about his team's opponents in the round of 16, saying he thinks his team-mates match up well to the skill brought to the table by Belgium.
He said, per Martin Pengelly of The Guardian:
They're a top team. Everyone around Europe will tell you how good they are. They've got so many good players, young players, strong, fast, good on the ball. I actually think because of that we match up well with them, but we'll see.
But Germany coach Joachim Low was less complimentary of USMNT after his side defeated them in the final match of Group G.
He said, per Pengelly:
The USA played very well in both their previous matches, although I was expecting them to show a little more initiative. USA dropped relatively deep and pulled everyone a long way back.
We were clearly the dominant team and our organisation was very good. With the exception of the last minute, we stopped them creating chances throughout the match. We showed lots of authority. We always knew it would be a fight right to the end.
Will USA beat Belgium?
If Belgium bring their A-game to the match with USA there is very little the Americans will be able to do to stop them. In Eden Hazard, the Red Devils have a player who is yet to show his best, but he always has that ability in reserve, and Jurgen Klinsmann will know this.
USA need to turn this into a battle; that will be their best chance of progression. The fact that extra time and penalties are now available gives the Americans an additional chance to win; it could be the case that they do indeed wear down and beat Belgium into submission.