DESPITE A FRUSTRATING opening 45 minutes in which it was badly outplayed, the U.S. men's national team burst out of the gates in the second half, scored a quick goal, and held off a determined Haiti squad to finish atop Group A in the 2015 Gold Cup with one game to spare.

Clint Dempsey scored the game's only goal in the 47th minute, his third in the tournament so far, off a Gyasi Zardes assist. 

Zardes, 23, came on for the Americans at intermission, replacing a struggling Jozy Altidore who is either injured, rusty, or both.

GOAL USA!! Zardes to Dempsey. 1-0. #USAvHAI pic.twitter.com/KznE5ZX3RD

— Ben Jata (@Ben_Jata) July 11, 2015

"He continues to show that he's a guy who can make a difference and a guy who needs to be a big part going forward," U.S. captain Michael Bradley said of Zardes after the match. "Tonight he came on and made a great play for us. We'll count on him to continue making big plays for us."

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Perhaps discouraged by the team's sloppy performance in a 2-1 win over Honduras on Tuesday—or perhaps just trying to mix things up—U.S. coach Jurgen Klinsmann made seven changes to the roster and switched from a 4-4-2 formation to a 4-3-1-2.

He replaced the entire backline, swapping out Fabian Johnson, John Brooks, Ventura Alvarado, and Timothy Chandler for Greg Garza, Omar Gonzalez, Tim Ream, and Brad Evans. Mix Diskerud, Graham Zusi, and Aron Johannsson also earned starts further up the pitch.

None of the changes seemed to help in the early going, as Haiti looked like the stronger of the two sides.

In the ninth minute James Marcelin picked Diskerud's pocket in the U.S. half and immediately initiatied a counterattack. Diskerud recovered and fouled James Marcelin but the gaffe gave Haiti a free kick from a dangerous position. Former Sporting Kansas City defender Mechack Jerome took the spot kick and delivered a lovely strike that beat Brad Guzan but kissed off the crossbar and into touch.

Twelve minutes later Haiti did more of the same. The visitors waited for a loose American pass, pounced, and countered with aggression and aplomb. In this instance, Wilde-Donald Guerrier had a free shot at Guzan's goal but his left-footed blast flew high and wide and out of play.

Through 25 minutes, Haiti had created two legitimate chances. And the United States? None.

Just after the half-hour mark the Americans gave the Haitians a taste of their own medicine: the team countered. In this instance Altidore found himself free in the left channel but rather than pushing forward he held up the ball and tried to find the perfect pass. He found Johannsson, who swiftly kicked the ball past Haitian goalkeeper Johny Placide, but the referee whistled him offside. (It was a very close call.)

A few minutes later Johannsson nearly created something out of nothing, dancing his way past several Haiti defenders to find a streaking Bradley in space. The U.S. captain dribbled forward but he mishit his left-footed strike and the chance went wasting.

The Yanks' best display of the opening interval came three minutes before intermission: Bradley lofted a pass to Johannsson in the left channel and he headed the ball toward Dempsey in front of goal. Haiti's defense held firm, however, and nothing came of it.

The U.S. pushed forward in the dying seconds of the first half, but Altidore's first touch let him down twice in key moments, letting Haiti off the hook and sending the two teams into the locker room in a scoreless draw.

Klinsmann apparently took note of Altidore's shoddy play, as he subbed off the 25-year-old striker in favor of Zardes. Sure enought, about 60 seconds into the second half Zardes created the go-ahead goal for the Americans.

It wasn't exactly a sequence  for the ages, but Zardes, playing on the left wing, made a proactive run down the flank, beat his defender, and then delivered a quick, simple cut-back pass to Dempsey—who buried the chance with conviction.

Emboldened by the goal—or perhaps empowered by Zardes coming on for Altidore—the U.S. began to take control of the game. Crisp passing and confident runs and possession-minded play gave the U.S. a bit of swagger and generated several solid scoring chances. 

But a hale and hearty Haiti wasn't about to give up. In fact, after nearly every U.S. gambit Les Grenadiers responded with their own attack.

Gonzalez and Ream played a clean match along the back line, however, and seemed to gain confidence as the game progressed. Still, Guzan had to come up big in the 56th minute, stoning Haiti's Duckens Nazon on a breakaway that seemed particularly promising. 

Klinsmann made another substitution in the 67th minute, bringing Fabian Johnson in at left back for Greg Garza, who gave a full-blooded effort but also turned the ball over a few too many times. The Borussia Mönchengladbach stabilized the U.S. defense and turned it a pair of crucial tackles that helped the Americans maintain their lead—including one off a Kyle Beckerman turnover in stoppage time.

The Yanks almost doubled their advantage in the 75th minute after some deft interplay between Dempsey, Bradley, Zardes, and Johannsson, the last of whom attempted an audacious bicycle kick that would have sent a charge through the 46,720 fans at Gillette Stadium if he had managed to connect.

As the game approached the 90-minute mark, both teams attacked with desperation. The Haitians were fighting for their Gold Cup lives. The Americans wanted to put an exclamation point on the contest in front of a vocal home crowd.

Although it had the better of the chances in the game's dying moments, the U.S. could not score a second and had to settle for a 1-0 victory.

In the opening contest at Gillette Stadium, Honduras and Panama played to a 1-1 draw, meaning that the U.S. opened the match knowing it would lock up first place in Group A with a victory over the 79th-ranked team in FIFA. 

The Yanks will now face Panama on Monday (9:30pm ET; Fox Sports 1, UniMas) knowing that no matter what happens in that match, they will get an advantageous draw in the knockout rounds.

John Godfrey is the founder and editor in chief of American Soccer Now. He shares his thoughts about soccer via Twitter.