Video of the horror incident shows that Yamak took a big hit from Wandera in the second round which wobbled him, according to The Sun.
Yamak was able to sit down on his stool at the end of the round but collapsed as he walked out one minute later.
Medics flooded the ring to provide first aid and revive him.
Yamak was then rushed to a local hospital, but was sadly pronounced dead of a heart attack on arrival.
A spokesman for the Munich police told BILD: "The paramedics saw turbulent scenes of emotionally charged fans and family members on site.
"To ensure the safety of the paramedics, we sent out a lot of patrols.
"We then set up a protection corridor on site so that the paramedics could work safely and conscientiously."
Germany-based Yamak boasted an undefeated 8-0 record, with all of his wins coming by knockout.
He only turned professional in 2017, but made waves last year after winning the WBFed international title.
Turkish member of government Turan earlier confirmed the tragic news.
"We lost our compatriot Musa Askan Yamak, a boxer from Alucra, who won European and Asian championships, at a young age after a heart attack," he wrote on Twitter.
"I wish God's mercy on the deceased, whom we met at the Grand National Assembly of Turkey when he came to Ankara for the competition, and my condolences to his sad family and fans."
