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(CNN) -- 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.