The sides were tied 1-1 after 90 minutes and Georginio Wijnaldum’s tame spot-kick, which was saved by Claudio Bravo, saw Pep Guardiola’s side win the season opener for the second successive year.
It was not plain sailing for Manchester City, though, despite taking the lead in the first half through Raheem Sterling.
The England forward’s hooked effort went underneath Alisson Becker, who was disappointed with his scrambled attempt to stop it crossing the line.
Liverpool came back strongly after the break, however, and created a swathe of chances in the second half with Joel Matip equalising in the 77th minute.
Mohamed Salah missed a litany of openings throughout the match and could have put the game to bed in stoppage time when heading into an empty net.
The Egyptian’s effort was acrobatically bicycle-kicked to safety on the goal line by Kyle Walker, though, which sent the FA exhibition to penalties.
Once Gabriel Jesus scored the decisive penalty, City players fist-pumped and ran towards each other to celebrate.
The Citizens, who have won the last five domestic trophies including Community Shields, tamely bounced up and down when lifting the shield, too.
Liverpool fans were quick to mock their rivals’ celebrations in what is seen by many as a glorified pre-season friendly.
“Why are City celebrating a friendly so much?” one Kopite asked on Twitter. “I think they should be worried after that performance, Liverpool all over them in the second half & all round better team through the game #LIVMCI.”
“Bloody hell, City celebrating like they’ve won the league,” observed another. “Couldn’t care less about losing this game, all about performance. A repeat of the second half against Norwich and I’ll be very happy! #LFC.”
Another fan wrote: “Man City celebrating like a small club when they have just won a pre-season alike trophy.”
“City celebrating a friendly win. Could never be us,” said another.
Among many who assumed a sarcastic tone, one rhetorically asked: “City won the league or community shield? Can’t judge by their celebrations.”