Arsenal continually caused chaos in the first half and Mikel Arteta's side led 3-0 at the break as a brace from Gabriel Martinelli was followed by a Bukayo Saka strike.
Leeds improved after the break and Joe Gelhardt earned the Whites a 75th-minute penalty after being fouled by Ben White, Raphinha blasting home the spot kick into the top right corner.
But Arsenal bagged a fourth goal with six minutes left when Martin Odegaard played in substitute Emile Smith Rowe who volleyed home past Illan Meslier.
Graham Smyth, the YEP's chief football writer, hands out the scores.
7. Mateusz Klich
4 - Better in the second half than the first, but Arsenal were comfortable by then. A couple of nice moments in attack. Photo by Naomi Baker/Getty Images.
8. Raphinha
5 - Leeds' best hope of a goal. Did so well in the lead up to a huge first half chance but couldn't finish. Took the penalty brilliantly. Photo by LINDSEY PARNABY/AFP via Getty Images.
9. Jack Harrison
3 - Made very little impression before going off with a knock he tried to run off. Always looked like he should be replaced but was kept out there for a surprising length of time. Photo by George Wood/Getty Images.
10. Tyler Roberts
4 - Struggled to pick the right option in the second half after a very quiet first half. Gave the ball away for the fourth goal. Picture by Bruce Rollinson.
11. Joe Gelhardt
5 - Plenty of running, tried his best to hold the ball up but was often isolated. Won a penalty, showed some glimpses of clever footwork. Picture by Bruce Rollinson.
12. Crysencio Summerville (sub)
5 - One of few bright spots on another dark day for Leeds. Lively on the ball, looked to get at Arsenal. Photo by LINDSEY PARNABY/AFP via Getty Images.