Chanin, of Bradenton, Fla., defeated Kyle Metzler 4-and-2 on Friday to advance to the semifinals at the Oak Hills Country Club in Racho Murieta, Calif.
He will now square off against Henry Liaw, who defeated Casey Wittenberg 3-and-1 on Friday.
Should Chanin go on to win, he will have eclipsed Tiger Woods as the youngest ever to have won the championship. Woods was 15 years, 6 months and 21 days when he took the title in 1991.
In the other semifinal match, Andrew Dresser, 17, of Carrollton, Tex. will take on Richard Scott, another 17-year-old who hails from Ontario, Canada.
Dresser beat Kevin Silva in 20 holes Friday to reach the semis, while Scott defeated Spencer Levin in 22 holes.
Scott is looking to become the first Canadian player ever to win the U.S. Junior Amateur.
The semifinals will commence at 8am Saturday, with the championship match to be contested afterwards at 1:30pm.
The U.S. Junior Amateur is one of 13 championships conducted annually by the United States Golf Association.
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