As the American sprinter was receiving the silver for his second place finish in the 100 meters, he noticed a spectator bothering his mother in the stands.
Gatlin pointed and yelled at the heckler.
"I was like, 'Hey, chill out with that. Be a gentleman,'" Gatlin told the Associated Press.
The 33-year-old is a polarizing figure in his sport. After winning the Olympic 100 meters in 2004, he served a four-year doping suspension and has fought his way back to the elite level amid continued suspicions.
His loss to Usain Bolt over the weekend was widely characterized as a victory for good over evil.