Canada responded 34 seconds into the middle frame, as Ethan Belchetz scored from the slot to tie the game.
Luke Puchner (New Germany, Minn.) regained the lead for the U.S. at 8:32 of the second, poking a rebound past Canadian netminder Gavin Betts following a shot from Brooks Rogowski (Brighton, Mich.).
Team USA took a 3-1 lead with 1:01 remaining in the second, as Zielinski found the back of the net after a net-front scramble to give the U.S. its second power-play goal of the contest.
The U.S. carried a two-goal lead into the third, outshooting Canada in the middle stanza, 18-5.
Ty Lawrence brought Canada within one 3:00 into the third, wristing a shot home on the power play. Mathis Preston tied the contest with a shot from the top of the right faceoff circle with 4:55 remaining in the third.
Knowling made a stellar pad save during the 10-minute 3-on-3 overtime frame, denying an opportunity near his crease with just under 5:00 remaining. Neither team scored during the overtime period, sending the game to a five-round shootout.
Joseph Salandra (Pleasantville, N.Y.) scored in the opening round of the shootout, sliding the puck through Betts’ five-hole. Nikita Klepov (Deerfield Beach, Fla.) found the back of the net in the second round, firing a shot from the slot past the netminder’s blocker.
Preston scored in the top of the third round, but Zielinski responded one shot later to give the U.S. a 3-1 advantage heading into the fourth.
Knowling shut the door on the fourth-round attempt from Canada to secure the victory for the U.S., sending his team to the championship game.
NOTES: Blake Zielinski was named U.S. Player of the Game … Canada outshot Team USA, 37-32 … The U.S. went 2-for-4 on the power play, while Canada went 1-for-4 with a man advantage … Team USA defeated Canada at the Hlinka Gretzky Cup/Ivan Hlinka Memorial Tournament/Junior World Cup for the first time since 2003 (4-3 OTW, semifinal).