Never beaten an ELITE team

I have been manager of Duisburg for the past 10 seasons, playing in the Bundesliga for the past 6. Highest finishing position 4th. Used many different tactics all with success currently using Knaps beowulf and rocksteady tactics and doing well in league and europe. BUT in all these years i have Never beaten an ELITE team..Bayern, PSG..any premier league team..Barcelona.

Any help on tweaks i can make that will help me. The tacgics i use can beat Dortmund, Sporting, Ajax etc but never the Elite.