The Germany legend expressed his excitement at the prospect of seeing the Pole at the Allianz Arena next season, even if it's at the expense of the current No.9
The Borussia Dortmund forward has signed a deal with the Bundesliga champions which will see him move to Pep Guardiola's side at the end of the season.
Beckenbauer, an honorary president for the Bavarians, believes Lewandowski will play a starring role at the Allianz Arena next season and hinted that he is better fitted under Pep Guardiola than Mandzukic.
When asked by 11 Freunde magazine if Lewandowski will make Mandzukic "pack his bags", Beckenbauer replied: "Yes. I assume that Lewandowski will be an immediate hit.
"His style fits Guardiola's tactics better that a pure box striker like Mandzukic. Plus, Pep could also put Thomas Muller or Mario Gotze up front."
The 68-year-old also reflected on the superiority that Bayern have shown in the last 18 months and believes it will continue for many seasons to come if they can keep adding world-class players to their squad.
"They are very hard to beat, no doubt about it," Beckenbauer said. "Especially if they keep reinforcing like they do. And they will!
"Pep Guardiola is the perfect coach and Matthias Sammer wakes them up if they're too relaxed. There is enough competition within the squad so they can be successful in all competitions. I do not see why that should change in the next years."