Thibaut Courtois and Alvaro Morata missed from the spot as Arsenal claimed the Community Shield by beating 10-man Chelsea 4-1 on penalties.
After a 1-1 draw in regulation time, the shoot-out saw goalkeeper Courtois, an unusual choice to take his side's second penalty, bizarrely firing his attempt way over.
That was followed by new signing Morata missing the target on his competitive debut, with Olivier Giroud going on to score the winning penalty.
In the match itself, Victor Moses, sent off when the Blues lost the FA Cup final to Arsenal in May, struck early in the second half with what looked like it would be the winner.
But Chelsea had Pedro sent off for a rash challenge on Mohamed Elneny and Arsenal substitute Sead Kolasinac, on his competitive bow, scored a header from the resulting free-kick with eight minutes remaining.
Alexandre Lacazette, given his Arsenal debut from the start, had earlier come the closest to a first-half goal, sending a strike against the post.
Arsenal have now won the Community Shield three times in the last four years, while the Blues have lost four consecutive appearances in the fixture.
Victory for Arsene Wenger's men means the Shield has seen the FA Cup winners beat the defending Premier League champions for four consecutive seasons.