The German champions produced a stunning display to dismantle Barcelona at the Allianz Arena to leave them with one foot in next month's final at Wembley.
Heynckes believes the tie is far from over and knows they must stick to their gameplan in the second leg at Camp Nou if they are to finish off the job.
"I am happy about the result, but I am not moved by it," said Heynckes. "I know that we still face 90 very difficult minutes in Spain.
"We will enjoy what happened tonight, but not more. It is important to stick to your tactical guidelines against Barcelona and that is what makes my team stand out this year."
Heynckes admits Bayern's hunger to make up for their disappointment in the Champions League in the last two years is the driving force behind their success this season.
"We have been displaying extraordinary football for the entire season now," added Heynckes.
"Falling short of success in the past two years has only made them more hungry to win this year.
"The tactical awareness of this team is top notch as well, just like their willingness to run and fight for one another. Today's game was a perfect example of that."