Liverpool's Roberto Firmino (left) competes with Manchester City's Oleksandr Zinchenko at Wembley Stadium in London on Sunday. Photo: IC

Manchester City struck an early blow for the forthcoming Premier League campaign as they beat 5-4 Liverpool on penalties to win the Community Shield at Wembley on Sunday after an absorbing contest had finished 1-1.

Former Liverpool player Raheem Sterling gave the English champions the lead in a first half they dominated as Liverpool's sluggish preseason form continued.

But European champions Liverpool were quicker and sharper in the second period.

They equalized through Joel Matip's header and created a host of other chances to take the lead as City appeared to tire.

City's Kyle Walker made a last-ditch goal-line clearance from Mo Salah's effort in the dying moments and with no extra time being played the showpiece went to a penalty shootout.

Pep Guardiola's side, who completed an unprecedented domestic treble last season after also winning the Community Shield curtain raiser, scored all five of their spot kicks.

Claudio Bravo's save from Liverpool's second penalty, struck by Georginio Wijnaldum, proved decisive as City once again displayed their appetite for the big occasion.

While neither manager will attach much significance to the outcome of Sunday's game, it was still a useful barometer of where both teams are, ahead of next weekend's big kickoff.

Sunday's evidence would suggest they will again be going toe-to-toe after City edged Liverpool by 98 points to 97 in winning last year's epic title race.

"The second half was a really good performance, really powerful," said Liverpool boss Juergen Klopp, who fielded nine of the 11 who started June's Champions League final against Tottenham Hotspur.

"I cannot be disappointed today. The performance was much more important today than a win. Now we know we are still here."

Guardiola believes City's Community Shield triumph against Liverpool was the perfect preparation ahead of this season's duel for supremacy between the Premier League rivals.

"There are two real contenders, Liverpool and us, to win the Premier League. [Manchester] United with [Harry] Maguire and the other players they bought, Arsenal, Chelsea and Tottenham can be there," Guardiola told reporters. "In the beginning of the season there are five or six contenders. Then the season will talk.

"I think it will be us and Liverpool, so it is good to see the team we will compete with, the champions of Europe."

Liverpool begin the Premier League season on Friday at home to newly promoted Norwich City while City begin their quest for a third consecutive title away to West Ham United.