Matti, a 13-year-old shortstop and leadoff hitter, also doubled and drew two walks. Both of his homers were solo shots, in the first and second innings, as New Jersey grabbed a 5-0 lead.
Oregon climbed within one by the end of the fourth, thanks to two-run singles from Ezra Samperi and Tyler Linch, but New Jersey put the game away with a run in the fourth and four in the fifth. Reliever Kyle Phillips hurled four shutout innings to nail down the win.
New England champion Fairfield, Conn., was the other United States team to advance. It broke a scoreless tie with a three-run third inning against Midwest champion Kearney, Neb., and cruised to a 12-0 win.
Matt Kubel earned the victory on the mound by striking out six over 4 2/3 shutout frames. He got plenty of support from an offense that racked up eight hits and seven walks.
Will Lucas' bases-loaded walk provided the game's first run, and Kevin Oriccoli added a two-run single in the inning. Lucas finished 2-for-2 with two walks, a home run and five RBIs, while Biagio Paoletta contributed two hits and drove in three.
In international play, Caribbean champion Willemstad, Curacao, used an eight-run first inning to grab control of its contest against European champion Germany, which hailed from Ramstein Air Base. The third batter of the game, Christopher Koeiman, blasted a three-run homer, and the rout was on. The game was stopped with Curacao leading 14-2 after four innings.
Meanwhile, the Little League World Series' first African team saw its run come to an end, as Lugazi, Uganda, fell 12-0 to Nuevo Laredo, Mexico, in four innings. Three pitchers combined on a perfect game and struck out nine for Mexico, which scored five runs in the second and seven in the third.
Andres Carrillo slammed two homers for Mexico, which collected a total of four for the second game in a row.
Sunday's slate at the tournament features a quartet of winners' bracket games. California will clash with Tennessee and Indiana with Texas in U.S. action, while Canada will take on Panama and Japan will meet Chinese Taipei on the international side.
The losers of those games will face the winners of Saturday's contests on Monday.