Answer
At Glory 12: New York, Petrosyan lost to Gokhan Saki by a knockout in the third round. This ended his undefeated streak of 28 fights. Saki was able to knock Petrosyan down in the first round, but Petrosyan was able to recover and win the second round. In the third round, Saki was able to land a series of punches that knocked Petrosyan out.