Arsene Wenger's team ended a nine-year trophy drought by beating Hull City in the FA Cup final in May and the north London club returned to the national stadium to produce an emphatic display in the traditional season curtain-raiser.
Injuries and late returns from World Cup commitments combined to leave City without seven of the XI that sealed a second Premier League title in three seasons with a final-day win over West Ham in May, but Arsenal were also missing Per Mertesacker, Mesut Ozil and Lukas Podolski, who helped Germany triumph in Brazil.
It was Arsenal who acquitted themselves to far greater effect in the first half, as showpiece new signing Alexis Sanchez, Jack Wilshere, Aaron Ramsey and Santi Cazorla all buzzed inventively behind Yaya Sanogo to torment City's outgunned midfield and makeshift back four.
Cazorla and Ramsey's goals for a 2-0 advantage at half-time were the least Arsenal deserved and, although David Silva's introduction sparked an improvement from City, fellow substitute Olivier Giroud secured the win with an excellent long-range effort.
Arsenal dominated the opening exchanges but clear chances evaded them, and it required a last-ditch challenge from Mathieu Debuchy to prevent Manchester City playmaker Samir Nasri from breaking the deadlock against his former club in the 14th minute.
That chance did nothing to turn the tide for the Premier League champions, for whom Yaya Toure and Fernando were being badly overrun in midfield and the opening goal stemmed from Arsenal exploiting generous amounts of space in front of City's back four.
Wilshere went to ground under a 21st-minute challenge from Dedryck Boyata but the ball broke to Cazorla on the edge of the box, who shifted the ball onto his left foot to finish clinically.
Sanogo dragged wide following Cazorla's searching ball in the 25th minute and Fernando lunged to block a drive from the Spain international as Arsenal continued to swarm forward.
Another debutant Arsenal defender, Calum Chambers, made a timely intervention to deny Nasri with the goal apparently gaping on the end of Aleksandar Kolarov's 39th-minute cross, but Wenger's men grabbed a deserved second three minutes before the interval.
City were torn apart on the break and Ramsey collected Sanogo's pass, evaded Matija Nastasic with a cute touch and slotted home.
Sanchez had chances to extend the advantage in stoppage time and a ragged City backline were relieved to hear referee Michael Oliver's half-time whistle.
Silva's impact was instant as City resumed on the front foot and Stevan Jovetic headed against the post from Jesus Navas' 51st-minute centre before blazing the rebound off target.
Jovetic then received Kolarov's cutback to draw a sharp near-post stop from Wojciech Szczesny - the Arsenal goalkeeper's first save of note.
But Arsenal sealed victory in style after the hour, as substitute Giroud lashed a dipping 25-yard strike beyond Willy Caballero's despairing dive, the recent signing from Malaga having been preferred to England's Joe Hart in Manuel Pellegrini's line-up.
City's performance will evoke uncomfortable memories of a pitiful title defence in 2012-13, although their launch of that campaign with a swaggering Community Shield win over Chelsea perhaps undermines this fixture as a useful form guide. Arsenal will hope this fine showing carries far more significance.
