Mexico put themselves on the brink of a 2014 World Cup bid in the opening leg against New Zealand last week, absolutely dominating for the entire 90-minute match en route to a 5-1 victory.
Simply put, the nation put itself into a heck of a position heading into the second and final leg in Wellington on Wednesday morning (6 a.m. GMT, 1 a.m. ET).
However, El Tri will have to go on the road—into a hostile environment in front of a nation desperately fighting to get a last-gasp bid—to close out this two-leg playoff.
And as told by France's comeback over Ukraine on Tuesday, anything is possible in the span of two matches.
Here are the biggest keys for Mexico as they look to hold on to a commanding, four-goal lead.
Don't Try to Replicate Game 1
I can already hear you: "But they won that game 5-1!"
However, the first leg and second leg will be very different matches from the get-go.
Early on in that first affair, New Zealand wanted nothing to do with possessing the ball and simply hunkered down on defense. That allowed Mexico to push the envelope at will, establishing an offensive set and eventually rattling off goal after goal.
That simply won't be the case in this second match. New Zealand—as home teams typically do in crucial matches—will be much more interested in possessing the ball and setting up offense (especially considering their massive deficit).
Mexico can play inspired defense when the situation calls for it, and this is undoubtedly one of those cases.
Avoid Recent Trend, Clamp Down on Defense Late
Mexico haven't been bad as a whole on defense in their recent World Cup qualifying struggles. The issue has been the offense more than anything.
But they've let up late goals at an alarming rate recently—a scary trend heading into a road match with a World Cup bid on the line.
In each of their last four World Cup qualifying matches prior to the playoff, El Tri gave up a second-half goal. Many of those (Costa Rica, United States) proved to be costly.
It took sheer luck for those late lapses to not spell doom for Mexico's World Cup bid.
Even though the first leg was all Mexico, they still gave up a late, 85th-minute goal to Christian James. It was a garbage-time goal, but it extended that streak to five.
Now, with a ticket to Brazil dangling in front of them, Mexico can ill-afford to give up another defensive lapse, or two, or three, late in this match.
If anything, it would be a sliver of discouragement in an otherwise likely joyous day for Mexico if they gave up another late goal—regardless of the playoff's outcome.
Play Like It's 0-0
As noted in the first point, Mexico can obviously afford to recede a little bit as far as attacking goes and be more defensive-oriented.
But that doesn't mean they should be playing like it's 5-1.
Mexico's head coach Miguel Herrera agrees. Per The New Zealand Herald's Michael Burgess, he'll be trying to win this match like any other:
"We are going to attack more [tonight]," said Herrera, "We want to win [this match] and we are going to win."
"We want to score early, to wipe out New Zealand's [away] goal," said Herrera. "We have an advantage from the first game but nothing more than that. The game starts again [tonight]."
Even though Mexico holds a four-goal lead in theory, this national team has shown a distinct trend of not possessing a lot of mental toughness. Players have rallied around Herrera as their new coach, but the critics of Mexico won't become quiet just after this seemingly fortunate World Cup bid.
Herrera is looking ahead past New Zealand by saying that he wants to beat them again. He knows that another decisive win in a match that hardly matters—short of a New Zealand domination—would only add to his team's sudden momentum.
After the summer this national team endured, they need all the momentum they can get.
Steven Cook covers breaking news for Bleacher Report. Follow him on Twitter.