Well, that was interesting.

In the wake of its comprehensive 6-0 defeat over Guatemala on July 5 and the subsequent 6-1 Gold Cup win over Belize on Tuesday, the United States men's soccer team seemed very confident heading into Saturday's contest against Cuba. In fact, the entire American soccer community appeared to be treating the Cuba match as a fait accompli.

And then Cuba scored first.

The Americans fought back to win, 4-1, but the match proved to be a real wakeup call for Jurgen Klinsmann's squad. A few players struggled badly in the first half, and it wasn't until the coach made several substitutions that the Yanks looked confident in victory.

With the result the U.S. advances to the quarterfinals of the Gold Cup, and will play a team to be determined on Sunday, July 21 in Baltimore.

The goal that changed everything, and seemed to signal the unofficial beginning of the 2013 Gold Cup (at least for the U.S.), was caused by two U.S. back line errors. Cuba's Ariel Martinez sped down the right flank, beat U.S. left back Edgar Castillo, and delivered a dangerous cross in the middle of the six-yard box. Oguchi Onyewu, wearing the armband as U.S. captain for the match, allowed Cuba's Jose Ciprian Alonso to beat him to the ball, and the striker slammed the ball past a defenseless Nick Rimando.

The crowd at Rio Tinto Stadium, not known for its boisterous nature, immediately fell silent. The Americans had fallen behind, at home, to the 82nd-ranked team in the world.

The Yanks quickly began playing with more urgency, and it paid off. The game-tying goal came on the heels of a nifty give-and-go exchange between Edgar Castillo and Landon Donovan. Castillo started the play with a pass into the penalty area, Donovan tapped it back, and then Castillo was tripped by a Cuban defender. On the ensuing penalty kick, Donovan shrewdly waited for Cuban goalkeeper Odelin Molina to dive his to left. Donovan shot in the other direction to even up the score.

The teams went into the break tied at one, but Klinsmann made one change at halftime, bringing in Jose Torres for a completely ineffective Brek Shea.

The move nearly paid immediate dividends. In the 49th minute, Torres sent in a lovely left-footed spot kick that Michael Orozco Fiscal slammed toward goal. Molina made a great reaction save, but the U.S. had regained the momentum.

And in the 57th minute, the Americans took the lead—for good. After a few sloppy passes, U.S. midfielder Joe Corona found himself in the right place at the right time and curled a 20-yard shot past Molina to give the Yanks a 2-1 lead. Corona looked solid throughout the match, playing smart, quick-passing soccer from start to finish.

Klinsmann made two more substitutions before the hour mark, taking off a frustrated Herculez Gomez and a largely invisible Stuart Holden in favor of Chris Wondolowski and Mix Diskerud. From this point on, the U.S. dominated.

Wondolowski, who scored a hat trick in the Gold Cup opener against Belize, added two more goals to his ledger. The first came on a simple-yet-precise cross from Kyle Beckerman in the 66th minute. The Real Salt Lake midfielder delivered a waist-high pass to the San Jose Earthquakes forward, who flicked the ball over the Molina's head and into the back of the net.

In the 85th minute, Wondolowski made it five goals in two matches when some sloppy Cuban defending gifted him a golden chance right in front of net. A pass from Torres bounced off Castillo and landed at Wondolowski's feet. He will never score an easier goal.

But the Americans will definitely face some tougher foes in this tournament. Although the team is guaranteed passage to the knockout stages of the Gold Cup, the Yanks will next face Costa Rica in East Hartford, Ct. on Tuesday.

That match should provide a sterner challenge for an American team that has now defeated three cupcakes in a row.

John Godfrey is the founder and editor in chief of American Soccer Now.