Arsenal beat German champions Bayern Munich 2-1 in their International Champions Cup opener with a late winner from Eddie Nketiah.
The Bundesliga champions equalised when forward Robert Lewandowski headed home a cross from ex-Gunner Serge Gnabry.
But an 88th-minute winner from 20-year-old substitute Nketiah handed Unai Emery's side the win in Los Angeles.
"Our responsibility in this club - for the history, present, and future - is to give young players a chance," Emery said.
"If they deserve minutes, they'll get minutes. I'm very happy with them."
Arsenal's victory followed on from Tuesday's 3-0 friendly win over Colorado Rapids.
They face two more matches in the United States, against Fiorentina in Charlotte on Saturday and then Real Madrid in Landover late on Tuesday.
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