Milan Jovanovic made the most of it, scoring one minute after German striker Miroslav Klose got ejected yesterday to give Serbia a 1-0 World Cup upset over the three-time champions.

Days after routing Australia, 4-0, in the tournament’s most impressive debut, Germany lost its momentum when Klose — the leading scorer at the 2006 World Cup — picked up his second yellow card.

Jovanovic scored a minute later, controlling a header and firing in a side-foot shot from directly in front of goalkeeper Manuel Neuer.

To make matters worse for Germany, Serbia goalkeeper Vladimir Stojkovic stopped Lukas Podolski’s penalty kick in the 60th minute. It was Germany’s first missed penalty in regular World Cup play since 1974.

“It was my fault. I missed,’’ Podolski said. “I accept responsibility and I don’t want to dwell on it.’’

Often considered the weak link on Serbia’s team, Stojkovic read Podolski’s penalty by diving to his left. The goalkeeper grabbed the ball when the game was over and stuck it under his jersey.

Serbia was part of the former Yugoslavia, which played Germany six times in a World Cup and only won in 1962. The last time Yugoslavia beat Germany in any match was in 1973.

“The second half was not 45 minutes, it was like two years for us,’’ Jovanovic said. “We beat Germany after 37 years, and it’s something real big for us.’’

With both teams using lone strikers, the match turned into a physical, often bruising contest in midfield, with Serbia allowing Germany little space for the kind of flowing, quick-passing moves it used in beating Australia.

Spanish referee Alberto Undiano handed out a tournament-high nine yellow cards.

“The referee made some strange decisions,’’ said Germany captain Philipp Lahm, one of those who was penalized.

Klose’s second yellow was the costliest for Germany.

Moments later, Serbia’s Milos Krasic chased a long ball to the sideline and swung a high cross to the far post, where Nikola Zigic headed it down for Jovanovic to volley in.

Jovanovic sprinted off the field and over a barrier to embrace the ecstatic Serbian fans.

The Germans’ best effort came in a hectic end to the first half, when Sami Khedira struck the crossbar and Thomas Mueller’s bicycle kick was cleared off the line by Serbian defender Aleksandar Kolarov.

“It was a difficult game, a very important game for us,’’ Stojkovic said. “This is a great victory for all of us. We have showed we are a good team and we believe in ourselves.’’

Both teams now have 3 points after two games in Group D. Ghana also has 3 points, and plays its second match — against Australia — today.