They didn't have to.
After grinding out its third straight win with a 2-1 victory against Denmark on Sunday, Germany finished top of a group that didn't end up being as dangerous as it looked on paper.
World Cup finalist the Netherlands was a major disappointment, losing all three Group B matches. Cristiano Ronaldo found his form just in the nick of time to take Portugal to the quarterfinals as runner-up to Germany.
And outsider Denmark just wasn't up to the task of repeating its upset from 20 years ago, when it stunned Germany to win the European Championship.
"I think we had the game well under control," Germany coach Joachim Loew said. "We had a lot of possession and I was sure that we would score and advance."
Germany next faces Euro 2004 champion Greece on Friday in Gdansk in a clash with significance beyond football, bringing together the two main protagonists — and occasional foes — in Europe's financial crisis.
If Germany and defending champion Spain keep winning, they will meet in the final on July 1.
Lukas Podolski opened the scoring for Germany in the 19th minute and Lars Bender slotted home the winner in the 80th after Michael Krohn-Dehli had equalized for Denmark in the first half.
"It's absolutely a day of joy," Bender said. "I'll be thinking back to this day a long, long time. We have a positive spirit in the team."
Germany played without flair, but controlled possession and were never really challenged by the Danes, who go home after stunning the Netherlands in the first match but losing to Portugal in the second.
Seizing the initiative from the kickoff, the Germans came close twice before Podolski, playing his 100th international match, scored his first goal of the tournament.
Mario Gomez set him up with a deft backheel touch following Thomas Mueller's low cross from the right flank.
"It was a special occasion to mark my 100th cap with a goal," Podolski said. "But the most important thing is that we are through to the knockout stage."
He was the seventh player to reach that milestone for Germany or West Germany.
Denmark replied just five minutes later with Krohn-Dehli heading in the equalizer from a set piece that stunned the German defence. A corner found Nicklas Bendtner who headed the ball into the area where Krohn-Dehli nodded home his second goal at Euro 2012.
"We should have gone ahead by two or three goals in the first half, but Denmark scored virtually out of nowhere," said.
Jakob Poulsen missed a chance to put Denmark in the driver's seat at the start of the second half when his shot grazed the outside of German goalkeeper Manuel Neuer's right post.
After that scare, the Germans were firmly in charge and denied Denmark any real chance of getting back into the game.
The Danes were already looking tired when Bender, replacing suspended right back Jerome Boateng, picked up a pass from Mesut Oezil and made it 2-1.
Coach Morten Olsen said the Spanish referee missed a penalty call when Bendtner was pulled down in the area but praised the Germans, saying they deserved to win the game and the group.
He dismissed suggestions his team should have tried to push back the Germans more boldly in the second half.
"They are dynamic and they are fast, so you need to watch out and not play too naively," Olsen said.
It was the first competitive match between the two countries since the 1992 European Championship final, when the Danes stunned the Germans with a 2-0 win to become champions.
Hoping for another upset, Olsen changed his lineup by moving playmaker Christian Eriksen to the right flank, replacing injured winger Dennis Rommedahl in a five-man midfield.
But the move had little effect as Philipp Lahm effectively closed down the talented 20-year-old, who leaves Euro 2012 without fulfilling expectations of an international breakthrough.
"We can be satisfied with our effort but not with the result," Denmark midfielder William Kvist said.
"I think we proved that we can play against the big teams. We won (against the Netherlands) and we didn't lose big. We showed that we can play against the best."
Denmark: Stephan Andersen, Lars Jacobsen, Simon Kjaer, Daniel Agger, Simon Poulsen, William Kvist, Christian Eriksen, Jakob Poulsen (Tobias Mikkelsen, 82), Niki Zimling (Christian Poulsen, 78), Michael Krohn-Dehli, Nicklas Bendtner.
Germany: Manuel Neuer, Lars Bender, Mats Hummels, Holger Badstuber, Philipp Lahm, Thomas Mueller (Toni Kroos, 84), Sami Khedira, Bastian Schweinsteiger, Mesut Oezil, Lukas Podolski (Andre Schuerrle, 64) Mario Gomez (Miroslav Klose, 74).