Originally Posted by Elevator Man
Actually before Stark pushes the missile through the wormhole and into the Chitauri "mothership", which destroyed Loki's army. Black Widow was about to close the portal by using Loki's scepter to shutdown the generator, which probably would've prevented anymore of Loki's army from getting through and ended the war. So Black Widow and Selvig already had a plan to stop the war before the third party interfered.
Another third party save. That wasn't the plan going in. Selvig woke up and mentioned the idea.
In MOS the plan worked but Zod did not go in the Zone. So they had to fight.