SALVADOR, Brazil— Thomas Mueller scored a hat trick as Germany turned on its style and power to rout 10-man Portugal, 4-0, in their World Cup Group G opener Monday.
Mueller, who scored five goals in the 2010 World Cup, was ruthless against a weak Portugal team that was clearly outplayed despite the presence of Cristiano Ronaldo.
‘‘To score three goals in the World Cup opener against such an opponent is great,’’ Mueller said.
With Chancellor Angela Merkel in the stands, the German team celebrated its 100th World Cup match with a rousing victory that was virtually assured by halftime.
‘‘After 20 minutes, we looked up at the clock and thought it was going to be a long day,’’ Mueller said. ‘‘But we got into the match very well and when you lead by 2-0 in this heat and then even get the third, it was all over.’’
Germany always aims to have an impressive start, and it certainly did this time. Four years ago, it started with a 4-0 win over Australia and reached the semifinals.
What must be worrisome for Germany’s opponents is the apparent ease with which Joachim Loew’s lineup disposed of the fourth-ranked team in the world. Germany next faces Ghana Saturday and the United States next Thursday.
Germany coach Joachim Loew said his team implemented his game plan very well, winning the ball in midfield and then quickly attacking.
Mueller scored on either side of Mats Hummels’s headed goal as Germany took a 3-0 lead at the break, and added his third goal in the 78th minute.
Ronaldo started at Arena Fonte Nova after overcoming a knee injury. He faded after threatening early in the match, including a shot from a break that Germany goalkeeper Manuel Neuer could only block, but there was nobody from Portugal to pounce on the rebound.
‘‘We lost the game already in the first half,’’ Portugal coach Paulo Bento said. ‘‘We couldn’t come back in the second. Germany played very well. We couldn’t do anything.’’
Portugal was already down, 2-0, before Pepe was red-carded in the 37th minute for apparently head-butting Mueller when the German player was sitting on the ground. Pepe had stuck his hand into Mueller’s face and the German went down.
‘‘I got hit, but after that, I am not really sure what happened,’’ Mueller said.
It was Mueller who opened the scoring in the 12th minute after Mario Goetze had been pulled down by Joao Pereira in the box, coolly slotting the penalty kick into the right corner of Rui Patricio’s goal.
‘‘I’ve been in some big matches before, so it’s not like I was afraid,’’ Mueller said.
Hummels had risen above Pepe to double Germany’s lead with a well-timed header from a corner in the 32d minute, and Mueller extended the buffer just before the break when he stripped the ball from Bruno Alves and drilled in a low shot.
The Bayern Munich forward completed the rout late in the second half, poking one in from close range after Patricio had fumbled a low cross from substitute Andre Schuerrle.
Germany could have scored more goals after the break, but Goetze and Mesut Ozil wasted good chances.