Officers arrived at the 9300 block of East Avenue O at about 10:20 p.m.
Upon arrival, they found the man had been shot in the back of the head.
According to HPD, the man was said to be with family watching Game 6 of the World Series outside when he said it felt like a hammer had struck him on the back of the head.
Police have said that they believe it was possibly celebratory gunfire since it occurred after the Astros beat the Philadelphia Phillies 4-1.
The man was taken to an area hospital and is expected to survive, HPD said.