Chelsea's goalkeeper Thibaut Courtois is beaten by a penalty during the English FA Community Shield match against Arsenal at Wembley Stadium in north London on August 6, 2017Chelsea's goalkeeper Thibaut Courtois is beaten by a penalty during the English FA Community Shield match against Arsenal at Wembley Stadium in north London on August 6, 2017 (AFP Photo/Daniel LEAL-OLIVAS)
Goals from Chelsea's Victor Moses and Arsenal new boy Sead Kolasinac sent the game to a shootout and with both Courtois and Morata limply squandering their spot-kicks, Arsenal won the trophy for the third time in four years.
Courtois blazed his penalty over the bar before substitute Morata, a Â£58 million (Â£75.6 million; 64.2 million euros) capture from Real Madrid, shot wide, allowing Olivier Giroud to seal victory for Arsenal.
"I'm very happy because we won a trophy we wanted to win and because the quality of the game was very good," said Arsenal manager Arsene Wenger after the shootout, which followed the new ABBA format.
"Even when we were 1-0 down, we didn't panic, kept control of our game and came back. The performance is in continuity of what we did at the end of last season."
Arsenal, embarking upon their first season without Champions League football since 1997, have won on their last nine visits to Wembley, a run stretching back to a win over Wigan Athletic in the semi-finals of the FA Cup in 2014.
Wenger's side open the Premier League season at home to 2016 champions Leicester City on Friday, with Antonio Conte's Chelsea beginning their title defence at home to Burnley the following day.
Moses, sent off after receiving a second yellow card for diving as Arsenal stunned Chelsea 2-1 in May's FA Cup final, partially atoned by putting the champions ahead early in the second half.
But after Pedro had been shown a straight red card for an ugly challenge on Mohamed Elneny, Kolasinac headed in an 81st-minute equaliser to leave the game 1-1 at full-time.
"For sure there is disappointment to finish for the second time with 10 men against Arsenal. Before the FA Cup, now the Community Shield," said Conte.
"You know very well we have to respect the referee's decision, but sometimes these decisions make you a bit angry."
- Mertesacker forced off -
As in the cup final, Arsenal made the more assured start and came within inches of opening the scoring when new signing Alexandre Lacazette curled a shot against the post after a slick counter-attack.
Per Mertesacker was one of the heroes of Arsenal's FA Cup win, expertly marshalling a badly depleted defence, but the club captain was to last just 27 minutes of the teams' reunion.
The giant German centre-back had to go off after a collision with Gary Cahill's elbow left blood streaming down his face, giving strapping Bosnian defender Kolasinac an opportunity to make his official debut.
As Arsenal reorganised, Chelsea began to assert themselves, Moses and Pedro working Petr Cech before Willian was harshly booked for diving after his left foot was clipped by Hector Bellerin's knee inside the box.
Neat footwork set Alex Iwobi up to curl a shot at Courtois late in the first half, but within a minute of kick-off in the second period, Arsenal found themselves behind.
Granit Xhaka's attempt to clear Willian's corner sent the ball looping into the air and when Cahill headed it back into the danger area, Moses darted in behind Rob Holding to apply an emphatic finish.
Wenger threw on Giroud and Theo Walcott for Lacazette and Iwobi and saw Xhaka extend Courtois with a 30-yard effort.
Pedro's dismissal for raking Elneny's left heel with his studs tipped the momentum in Arsenal's favour and they equalised when Xhaka's cross from the ensuing free-kick was headed in by Kolasinac.