With victory in the first leg of the semifinal, Dortmund, the only unbeaten side remaining in the competition, made it six wins in six at home and extended Madrid’s run of six consecutive defeats in Germany.
Lewandowski opened the scoring in the eighth minute, only for Cristiano Ronaldo to equalize against the run of play two minutes before the interval. Lewandowski beat the offside trap in the 50th for his second goal, and the Poland striker completed his hat trick in stunning fashion five minutes later.
”It was an outstanding game from my team,” Dortmund coach Juergen Klopp said. ”The third goal was worth every cent (broadcasters) ZDF and Sky give us.”
Dortmund midfielder Ilkay Guendogan, playing on the Madrid club’s name, said: ”It was a royal evening for us.”
The only unbeaten side remaining in the competition, Dortmund made it six wins in six at home and extended Madrid’s run of six consecutive defeats in Germany.
”I could see there was one team on the pitch that was much better than the other. The better team definitely won,” Madrid coach Jose Mourinho said after his worst result as a coach in the Champions League.
Lewandowski took his chance a minute later, however, when Ilkay Guendogan sent Goetze free down the left, and the 20-year-old whipped in a dangerous cross that Lewandowski managed to reach ahead of Raphael Varane and Pepe.
Mesut Oezil almost played Ronaldo through as the visitors sought a response, but the pass was too far ahead of the Portugal star.
The visitors’ troubles with Dortmund’s pressure were summed up when Alonso went back to collect the ball from his goalkeeper, only to put a long pass out over the sideline.
Ronaldo brought a smart save from Roman Weidenfeller with a free kick, before Guendogan shot over at the other end as the visitors resorted to last-ditch defending.
Dortmund’s forays forward had the crowd on their feet, rising to the occasion as they sensed something special was happening.
”Without this atmosphere this game would not have been possible,” Klopp said. ”One hundred percent.”
Penalty appeals were waved away after Reus fell under Varane’s challenge in the area, and the home fans had further ground for complaint when Gonzalo Higuain seized on Mats Hummels’ weak back pass and rolled it across goal for Ronaldo to fire into an unguarded net.
It was his 12th goal of this season’s campaign in Europe and his 50th in the Champions League overall.
The game was being played at such a frenetic pace after the break that both sides found it hard to complete passes.
However, Lewandowski ran onto Reus’ defense-splitting pass before tucking the ball past goalkeeper Diego Lopez, and he did even better five minutes later when he eluded Pepe by dragging the ball back and hammered the ball home from close range.
Lewandowski notched his fourth from the spot five minutes later, and could have even had a fifth late on, only to be denied by a flying save from Lopez.
Though Dortmund will be looking for only its second appearance in the final – having won the competition in 1997 – Mourinho refused to give up hope of Madrid reaching a 13th European Cup final.
”In football everything is possible,” Mourinho said. ”Anything can happen next week.