Jarrett Anton delivered the game-winning hit and went two for four with two runs batted in, and pitcher Ryan Abady (3-1) held Valley Christian hitless in his 1 1/3 innings of relief work to get the win, in the championship game.
The four victories extended Huntington's win streak to 12 games. The Oilers, the top-ranked team in CIF Southern Section Division 1, improved to 15-2 overall.
Huntington junior Daniel Amaral was named tournament MVP. The Oilers' Noah Davis, who earned the win against IMG Academy in the April 16 semifinals, was named Pitcher of the Tournament.
Senior Jake Brodt, who had the game-winning, walk-off RBI double to beat Santa Margarita April 15, was named to the all-tournament team.
"The National Classic is a very prestigious tournament, so just to be invited to it is an accomplishment," Medure said. "To win the whole deal is something that is hard to believe.
"I remember 14 years ago when I first got the job, thinking that we would never even get a chance to play in the tournament. Now, here we are, with the trophy. It's awesome."
•Fountain Valley also competed for the title of the Hard 9 National Classic, and the Barons split their four games at the tournament. They ended their run with a 7-0 victory over Sunrise Mountain (Arizona) in the seventh-place game April 17.
Daniel Patzlaff and Daniel Rosica each had two hits and Scott Schultz earned his eighth win of the season in the Barons' tourney finale.
Patzlaff, who went six for 12 in four tournament games, and the undefeated Schultz, who struck out seven and didn't allow an earned run in the tournament, both made the all-tournament team.
Fountain Valley headed into the week 13-6.