On Aug. 15, 2012, the United States won against their bitter rival Mexico on Mexican soil for the first time in their competitive history.
Everything had to go right for the Americans that day to end an astounding streak of Mexican dominance at home, and for 90 minutes, everything did in their 1-0 victory.
Unfortunately, it was only a friendly, and wins in friendlies don't qualify a squad for the World Cup.
Tonight, it counts for more than just bragging rights.
The Mexican national team had its ego bruised in August, and Chicharito Hernandez and El Tricolor will be more than ready to use their home-field advantage to teach the USA a lesson while strengthening their bid for a spot in the 2014 World Cup.
The moment Mexico puts in a goal, the entire Estadio Azteca will explode, and the incredible atmosphere in Mexico City will make the Americans' improbable dream of another victory in enemy territory an impossible one.
That's what makes Brad Guzan the most important man on the pitch for the United States.
Guzan will be tasked with continuing his excellent run of form and managing what isn't the most convincing of USA back lines.
Only Geoff Cameron remains as a defender from the American side that beat Mexico in 2012 in tonight's predicted lineup.
And while this relatively new defensive line helped to keep a clean sheet against Costa Rica, it's hard to tell how much of a factor the poor weather played in the low-scoring affair.
Will the United States keep a clean sheet against Mexico?
Regardless of the weather's effect in Costa Rica, a match against Mexico will be a much tougher test for Omar Gonzalez and Co.
Snow certainly won't be a potential excuse in Mexico City.
Guzan has been splendid in the Premier League this season and is one of the main reasons Aston Villa have managed to creep outside the relegation zone.
However, in order to beat Mexico, he will have to live up to the standard set by the injured Tim Howard and keep a clean sheet.
If the U.S. is to triumph against all odds once again, they cannot allow Mexico to score, and with a player like Brad Guzan between the posts, America will always stand a chance.