Despite losing the game - Bayern's last warm-up fixture in their training camp in Trentino before flying out to China - Heynckes says he learned more about his team than he would have done from facing a lesser opponent.
"I was pleased with the performance of my team over long stretches," he said on his club's website.
"It was a more valuable and good test which provided more information than if we had beaten a team 11-0."
David Alaba scored Bayern's first goal before later leaving the field injured.
Xherdan Shaqiri was also on target for Bayern, with Paolo Cannavaro, Goran Pandev and new signing Lorenzo Insigne netting for Walter Mazzarri's Napoli.