The first half witnessed no goals, but Victor Moses opened scoring in the second half. The Super Eagles forward capitalized on a static Gunners defence, to slot pass Pete Cech.
Sead Kolasinac, who arrived as a free agent this summer, levelled the game late on with a header from Granit Xhaka’s free kick.
The game was eventually decided on penalties using the ABBA system.
Thibaut Courtois and Alvaro Morata missed from 12yards, as Arsene Wenger’s men opened the season with victory.