World Cup: German fire dismantles Portugal castle, USA smiles at the end - PHOTOS

As World Cup openers go, this was about as bad as it gets for Portugal.

Thumped 4-0 by Germany, one key defender sent off, another possibly out of the tournament with injury and its World Player of the Year looking decidedly unfit.

Real Madrid star Cristiano Ronaldo wasn't lacking in effort but was as powerless as those around him to prevent Portugal being steamrollered by Der Mannschaft in Salvador.

It started badly for Paulo Bento's men and got steadily worse as Germany maintained its record of scoring at least four goals in every opening World Cup match since 2002.

They were 1-0 down after 10 minutes when Joao Pereira was adjudged to have hauled down Mario Gotze. Fellow Bayern Munich star Thomas Muller confidently slotted home the penalty.

It was 2-0 when Mats Hummels thumped a header into the net from Toni Kroos' corner.

Just five minutes later, Real Madrid defender Pepe tangled with Muller, who sank theatrically to the turf claiming a hand to the face.

Pepe then stood over his opponent and pushed his head towards Muller's, the referee producing a straight red card.

Muller then struck just before the interval to put the game well beyond Portugal, pouncing on a loose ball inside the area to fire past Rui Patricio.

Portugal made a change at the break, as Ricardo Costa replaced Miguel Veloso, but it made little difference as Germany continued to press home their advantage.

Mesut Ozil, who plays for Arsenal, should have found the net when played through on goal but he hit his shot straight at Patricio.

With Pepe already off the field, another Portuguese defender joined him -- this time through injury rather than red card -- when Fabio Coentrao pulled up with what looked like a hamstring injury and departed on a stretcher.

Germany squandered several counter attacking opportunities before Muller completed a memorable hat-trick on 78 minutes, stabbing a shot into the net after Andre Schurrle's cross had been parried by the goalkeeper.

The 24-year-old was top scorer at the last World Cup in South Africa, netting five goals in six games. He now has 20 goals in 50 internationals for Germany.

Ronaldo nearly opened his World Cup account in stoppage time but Manuel Neuer saved brilliantly from his fierce free kick.

"Winning was our only option and the team went out there with that in mind," Germany coach Joachim Low was quoted as saying by FIFA's official website.

"Thomas (Muller) did really well in attack and created a lot of space for us."

Iran 0-0 Nigeria

Meanwhile in Group F, Iran and Nigeria shared the first draw of the competition in Curitiba.

It was the 13th match of Brazil 2014 and it proved unlucky for football fans as it finished in a stalemate.

Both teams struggled to create goalscoring opportunities in a drab contest, although Iran missed a golden chance in the first half.

Iran's first corner gave striker Reza Ghoochannejad the chance to open the scoring, but Nigeria goalkeeper Vincent Enyeama stretched to save his near-post header.

Nigeria, crowned African champions in 2013, were expected to win the game comfortably but the "Super Eagles" failed to seriously threaten the Iranian goal.

The result leaves Argentina top of the group after a 2-1 win over Bosnia and Herzegovina on Sunday.

Iran faces Argentina on Saturday in Belo Horizonte, while Nigeria travels to Cuiaba to play Bosnia.

USA 2-1 Ghana

Substitute John Brooks' headed goal four minutes from time gave the United States a dramatic 2-1 victory over Ghana in a Group G opening round World Cup match on Monday.

Brooks scored from a corner kick just four minutes after Andre Ayew of Ghana equalized by giving Ghana the goal that had eluded its grasp much of the night.

Clint Dempsey had given the United States a 1-0 lead with the quickest goal ever for the U.S. in a World Cup match.

He netted just 30 seconds into the match, breaking into the penalty area and striking home a left-footed shot past sprawling Ghana goalkeeper Adam Kwarasey.

"We have a great spirit and (we) fight until the last second," U.S. coach Jurgen Klinsmann said. "There is undoubtedly things that we need to improve. At the end of the day we got the three points."

The 2-1 scoreline was familiar but a turnaround from the 2006 and 2010 World Cups when Ghana eliminated the United States each time by the same score.

After a frustrating first half, Ghana threatened more often in the second 45 minutes, finally getting the goal that seemed would be their destiny eight minutes from the end.

Ayew finished neatly with the outside of his left boot after a flowing move that saw him collect a back heel from striker Asamoah Gyan.

The favored Ghanaians spent much of the game in the U.S. end. They often knocked the ball around as the Americans sat back on defense, trying not to be beaten by the Africans' speed.

Ghana, the youngest team in the tournament, attacked incessantly down the right side of the field in the first half, only to be undone by poor crosses that sailed high and wide.

The United States chose to rely on counterattacks and in the 19th minute almost doubled its 1-0 lead when striker Jozy Altidore had a good chance that was thwarted by a sliding defender.

It was heartbreak for the young American, who left the match with a hamstring injury two minutes later. He was replaced by Aron Johansson.

The Americans spent much of the second half chasing the ball and only mustered a Dempsey shot in the 79th minute that was easily saved by Kwarasey until Brooks' stunning goal, his first in an international match.

U.S. goalie Tim Howard had four saves. Kwarasey had three.

The United States faces Portugal on Sunday, while Ghana plays Germany on Saturday.


/CNN/