Arsenal lifted the Community Shield to end Manchester City's silverware streak with a 4-1 penalty shoot-out victory after a 1-1 draw against the treble winners on Sunday.
Mikel Arteta's side forced the shoot-out thanks to Leandro Trossard's heavily deflected equaliser 11 minutes into stoppage time at Wembley.
De Bruyne hit the bar with City's first spot-kick and Rodri's effort was saved by Aaron Ramsdale, while Arsenal converted all four of their kicks.
Arsenal's celebrations were far more frenzied than would normally be seen in what in the glamour friendly, but their jubilation underlined the months of anguish endured since they blew a golden opportunity to win their first title since 2004.
City made history by becoming only the second English club to lift the Premier League, Champions League and FA Cup in a single season last term.
Their fifth Premier League title in six seasons came at Arsenal's expense as the Gunners wasted the eight-point lead they held at the start of April to finish five points behind the champions.
Showcasing œ160 million worth of new signings in Declan Rice, Kai Havertz and Jurrien Timber, it was clear Arsenal had a point to prove to City as they snapped into tackles with the kind of urgency that usually accompanies a title decider.
Inevitably, it was City who bucked that trend in 2018 and it is far too early to bet on Arsenal following in their footsteps.
Arsenal led the table for 248 days last season and still fell short, prompting Arteta to admit they will need an "unheard of" points total to stop the champions this term.
- Composed Rice -
Pep Guardiola's men, aiming for an unprecedented fourth successive Premier League crown, start their title defence at promoted Burnley on Friday, while Arsenal host Nottingham Forest the following day.
Arteta will have been encouraged by a composed display from England midfielder Rice following his œ105 million move from West Ham.
Timber, another new recruit, was also solid at left-back but Havertz was typically profligate as he wasted Arsenal's two best chances to take the lead.
Havertz will be expected to lead the Arsenal attack while Gabriel Jesus recovers from knee surgery and this was hardly the ideal introduction to his new club for the inconsistent German.
Mateo Kovacic was energetic on his City debut after the midfielder's move from Chelsea, but fellow Croatian Josko Gvardiol was unavailable following the defender's arrival from Leipzig on Saturday.
Palmer was the anonymous Erling Haaland's second half replacement and the promising youngster netted in the 77th minute.
City broke at pace and when Kieran Tierney lost the ball carelessly, De Bruyne's header found Palmer and he curled a sublime finish into the far corner from the edge of the area.
But in a sign of things to come under the new time-wasting rules, there was a huge amount of stoppage time and Arsenal snatched the equaliser 11 minutes into the additional period.
It was a hugely fortunate goal as Trossard cut in from the right and hit his shot straight at Manuel Akanji, only for the ball to deflect off the City defender past the wrong-footed Stefan Ortega.
Still feeling the pain of last season's title collapse, Arteta celebrated as though Arsenal had won the league.
The Spaniard let his emotions hang out again when Vieira converted the winning penalty to light the fuse on the looming title race.