Argentina's Carlos Tevez (right) scores the team's fourth goal as Jay DeMerit of the U.S. fails to stop him in the Copa America tournament in Maracaibo on Thursday night. Argentina won 4-1. - Reuters

PUERTO LA CRUZ, Venezuela (Reuters):

PARAGUAY, INSPIRED by a Roque Santa Cruz hat-trick, thumped Colombia 5-0 while Argentina overpowered the United States 4-1 in a glut of goals at the Copa America on Thursday night.

Favourites Argentina survived an early fright against inexperienced opponents, going behind to an Eddie Johnson penalty before two Hernan Crespo goals set them on the way to an impressive win.

Colombia striker Alvaro Dominguez missed a penalty two minutes before Paraguay opened the scoring in the first game of the Group C double bill in Maracaibo.

The result prompted Colombia coach Jorge Luis Pinto to apologise to his countrymen.

"I lament the score," he said. "I'm sorry for Colombia and for my country."

Argentina had Juan Roman Riquelme back in the side after going back on his decision to quit and Juan Sebastian Veron playing his first competitive international since 2003 but looked in trouble early on.

Johnson won and converted a ninth-minute penalty to give the United States, who are playing as Copa guests and brought an experimental team, a shock lead.

Crespo equalised two minutes later but Argentina were then frustrated by a packed U.S. defence for nearly an hour.

Crespo finally put Argentina ahead in the 64th minute, running on to Lionel Messi's pass to place his shot beyond Kasey Keller.

Two more late in the game

Substitutes Pablo Aimar and Carlos Tevez added two more late in the game as their opponents were forced to open up.

"We knew it was going to be hard and that they would defend all the time," said Riquelme.

"But we played with patience. We knew we had 90 minutes and we were always sure we would win the game."

Colombia dominated the first half of the opening game but squandered an excellent chance in the 28th minute when Dominguez's penalty was saved by Justo Villar.

Two minutes later, Santa Cruz broke clear of the defence to put Paraguay ahead.

The Bayern Munich striker added another just 22 seconds after halftime and completed his treble in the 79th minute.

Substitute Salvador Cabanas compounded Colombia's misery by adding two more in the closing minutes.