Leeds impressed in the first half but substitute Calum Chambers put Arsenal ahead with a header from a corner in the 55th minute, netting with his first touch of the game and 23 seconds after his introduction for the injured Ben White.
After a header from captain Liam Cooper to goalkeeper Illan Meslier fell short, former Whites loanee Eddie Nketiah then doubled Arsenal's lead in the 69th minute.
Graham Smyth, the YEP's chief football writer, hands out the scores as Leeds squandered an opportunity to book a place in the quarter-finals.
Graham Smyth, the YEP's chief football writer, hands out the scores as Leeds squandered an opportunity to book a place in the quarter-finals.