It all happened in less than five minutes, and it was caught on camera.
Just before midnight, two police officers, Officer Jared Levitt and Sergeant Dave Hockett, arrived on Ninth Avenue to find a man overdosing on heroin.
They immediately injected him with a drug called Naloxone, or Narcan, which reverses an overdose.
They also start performing CPR.
"Every time we save someone's life, that's someone who gets a second chance," said Penny Legate, who led the effort to raise $5,000 last spring so all of Seattle's bike officers could carry Narcan.
Legate's daughter, Marah, died from a heroin overdose.
"I have such mixed feelings," said Legate. "Joy the person is alive. Sad they're in the predicament, using heroin."
SPD says this is the 17th time its officers have saved someone's life using the drug since they started carrying it last March.