Tristin Saghin, 9, was visiting his grandmother in Mesa, Arizona when his 2-year-old sister was found floating in the backyard pool.

"I just went running outside again, and I did CPR on her," Tristin told ABC15. "I knew what I was doing." He said he learned CPR from watching television, and performed chest compressions and mouth-to-mouth resuscitation on his unconscious sister, who is in the hospital and expected to fully recover.

Meet this super kid!