Clarke entered the competition with the best throw in the nation by a high school athlete, a 67-foot, 10 3/4-inch toss he uncorked just a week ago.
One throw into Friday's competition, that mark was erased as Clarke unleashed a 68-foot, 7.5-inch toss.
And on the fourth throw of the meet, Clarke broke the 70-foot barrier with his record toss.
"He doesn't choke," said John Schmitz, Bartlett's head track and field coach. "He's a natural."
Clarke, who is headed to Arizona State University on a track scholarship next season, has improved his shot put every year at Bartlett, starting with a 47-foot, 9.5-inch throw as a freshman that was fourth best in the state. He added 12 feet as a sophomore, nearly two feet as a junior and now nearly nine feet as a senior.
Clarke will make his final throws for Bartlett in Saturday's discus event, where he is also the state record holder.
Ian Rosario of Chugiak finished second Friday with a 49-foot, 3/4-inch throw in the shot.
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