The U.S. goalkeeper was unable to cut down the angle after diving to punch away a deflected ball, and Mueller did what he does so well - calmly drive a first-time shot inside the far post for his ninth goal in nine career World Cup games, giving Germany a 1-0 victory.
''I saw the ball ricochet toward me, away from the goal keeper,'' Mueller said, a bandage and stitches over his right eye from a collision in his previous match. ''I just focused on the ball and the far post, and I hit the ball the way I thought I would hit it, and that's it.''
That's it, indeed. Germany wins again.
The 24-year-old Mueller isn't flashy, and didn't generate the pre-tournament talk of Brazil's Neymar or Portugal's Cristiano Ronaldo. But the Bayern Munich star is tied with Neymar with four goals in Brazil after scoring a tournament-high five in South Africa.
Mueller opened Germany's campaign in Brazil with a hat trick that powered his side to a stunning 4-0 demolition of Portugal. The result wound up helping the United States, which finished Group G play tied with Portugal on points for second, but with a better goal difference after holding the Germans to only Mueller's searing right-footed, 18-yard strike.
''Every nation in the world would love to have Thomas Mueller on their team. That's without question,'' U.S. coach Jurgen Klinsmann said.
Though failing to score in Germany's 2-2 draw with Ghana, Mueller didn't spare his body in an effort to find a match winner. Sprinting into the penalty area for a long ball as time was running out, he was involved in a hard collision which left blood all over his face.
He needed five stitches to sew up the damage. During the past week, he said he doubted he'd be pain-free against the U.S., but should be well enough to play without painkillers.
Mueller certainly looked like his old self on Thursday, lifting Germany to the top of its group ahead of the knockout stage with his 21st goal in 51 international appearances.
Germany's Mats Hummels said Mueller's qualities as a teammate don't stop at his technical skills.
''He's very motivated and knows how to motivate others. Outside the pitch he's a very funny guy,'' Hummels said.
With seemingly numerous World Cup games in his future, Mueller is now six goals shy of the all-time World Cup record, held by his veteran teammate Miroslav Klose and former Brazil striker Ronaldo.
On his current form, there's every reason to think Mueller will add to that tally in Brazil.
''Right now he is very difficult for any opponent to figure out and it's difficult to stand against him because he's a very smart player and he finds always a way to go into the area,'' Germany coach Joachim Loew said.
''He's been in great shape for weeks, and you have the impression it's so easy for him.''
Yet Howard, whose dive came up short, said Mueller's shot was by no means routine.
''Credit to Mueller. Keeping that shot hard and low, first time, is very, very difficult. He's done it before, but that's the type of player he is,'' Howard said. ''I thought I read it well, but it was a great finish.''
AP Sports Writers Janie McCauley and Nesha Starcevic contributed to this report.