Alvaro Morata missed a penalty on his Chelsea debut as Arsenal won an uncharacteristically feisty Community Shield in a shootout at Wembley.
Record signing Morata a late substitute dragged a poor effort wide moments after goalkeeper Thibaut Courtois had blazed over in a first use of a new penalty shootout system.
Premier League champions Chelsea had gone ahead through Victor Moses, before Pedro was sent off for an ugly lunge on Mohamed Elneny.
From the resulting free-kick, debutant Sead Kolasinac headed the Gunners level to take the match to penalties.
The shootout the first in English football to follow the format saw Chelsea miss back to back penalties to allow Olivier Giroud to win the match from the spot.
Level at 90 minutes, the match went straight to penalties, which were taken in the (ABBA) format.
After Gary Cahill’s opener for Chelsea was cancelled out by Theo Walcott, Arsenal defender Nacho Monreal stepped forward, correctly, to take his kick.
However he was waved back by several of his Gunners team-mates, who seemed confused by the new format.
Monreal scored, before Courtois and Morata both missed horribly, to the delight of the Arsenal fans behind the goal.
That allowed first Alex Oxlade Chamberlain and then Giroud to score and start the Arsenal celebrations.
Until the red card, it looked like being victory for the champions, who shook off a sleepy first 20 minutes to have the better of the game.
They deservedly took the lead in the opening minute of the second half as Granit Xhaka’s dreadful clearance from a corner was headed back in by Gary Cahill for Moses to finish with opportunism.
It looked a long way back from there for Arsenal, especially as they were without key duo Alexis Sanchez and Mesut Ozil, left out of the squad altogether by Arsene Wenger.
Sanchez only returned to training on Tuesday after illness, having taken an extended break following his participation in the Confederations Cup with Chile, while Ozil picked up a minor knock in training in the week and was not risked.