Hirving Lozano grabbed the only goal at the Luzhniki Stadium in Moscow to delight the hordes of boisterous Mexican supporters and consign defending champions Germany to their first opening-match defeat at a World Cup since 1982.
Victory was no more than Mexico deserved for a high-octane first-half display and a stout defensive performance after the break when Joachim Low's men cranked up the pressure.
Osorio said: "We had drawn up a plan six months back but, due to injuries, we had to change some of our players.
"We always thought, though, of having two quick players on the wings and an offensive midfielder in Miguel Layun.
"In the first half we played with defensive intelligence and caught them on the counter. We could have scored earlier.
"In the first half we were the better side, in the second we knew that Germany have an outstanding team and they tried to attack more."
Low threw on burly striker Mario Gomez as a final roll of the dice but Osorio had a plan for that as well.
He added: "We prepared for their use of Mario Gomez. Yesterday we practised defending with four midfielders and three players up front and that’s how we almost got the second goal.
"We played for the joy of winning, not the fear of losing, We played with bravery, and defended with all our hearts.
"I think this is a milestone for Mexican football, more attention will be played to Mexican players. It's important for Mexican football to grow."
Lozano was named man of the match for an effervescent display, capped with a clinical finish after 35 minutes.
And the 22-year-old PSV forward revelled in the biggest goal of his young career.
He said: "We all dream about playing in a World Cup and to start in such an amazing way.
"It's the most important goal I have ever scored. It's a great start for the team, to get off on the right foot when you are playing against the world champions.
"My team-mates and I ran our hearts out, put in a lot of work and this is the result."