Damar Hamlin is officially back ... the Buffalo Bills safety was a full participant at practice with his teammates for the first time since going into cardiac arrest in January.
The Bills hosted OTAs on Tuesday ... and 25-year-old Hamlin got his first taste of real NFL practice action in five months.
There was a bit of a scary moment for Hamlin and the Bills ... he reportedly struggled to get back to his feet after contesting a ball during practice, needing assistance to get up.