Ronaldo has netted a competition-high 15 goals in the Champions League this season and has 41 in all competitions, compared to 39 for Lewandowski in six games fewer.
No player boasts better form than the Portuguese since the turn of the year, however, and Heynckes admits that Bayern must be alert to stop the threat the prolific forward poses in the first leg of their Champions League semi-final showdown.
"I respect Cristiano Ronaldo. He has had a superb career. But you need to play well as a team to win the Champions League," he told reporters ahead of Wednesday's clash at the Allianz Arena.
"We analyse our opponents and prepare to beat them. In Robert Lewandowski, we also have a striker who has already scored 39 goals this season. So you might ask: how do you stop Lewandowski?"
Poland international Lewandowski recently attempted to play down talk of a move to Madrid.