MELBOURNE (AFP) - Record signing Raheem Sterling took just over two minutes to score his debut goal as Manchester City downed AS Roma on penalties in the International Champions Cup in Melbourne on Tuesday.

England goalkeeper Joe Hart made two late saves as City won 5-4 after the penalty shootout at the Melbourne Cricket Ground.

Sterling, the most expensive English footballer in history, took just two minutes and 17 seconds to open his account for the big-spending English club.

He showed his explosive pace to swoop on a defence-splitting pass from Kelechi Iheanacho to leave Roma goalkeeper Morgan de Sanctis flailing and slot the ball into the empty net.

While Sterling's much-anticipated first appearance in the sky blue was the major talking point, the 2014 English Premier League champions showed plenty of attacking promise for the season ahead.

The 20-year-old Jamaican-born Londoner completed his move to City from Liverpool last week in a five-year deal worth an initial £44 million that could rise to £49 million ($104 million).

The Italian side equalised just five minutes after Sterling's strike when Bosnian midfielder Miralem Pjanic let fly with a 20-metre thunderbolt into the top right corner.

Manager Manuel Pellegrini took Sterling off at half-time along with the influential David Silva in wholesale changes, introducing Samir Nasri, Aleksandar Kolarov and Yaya Toure into the game.

Nigerian teenager Iheanacho put City ahead again on 51 minutes when he zeroed in on an awful back pass by Ashley Cole to coolly beat de Sanctis from close range.

But Serbian Adem Ljajic threw Roma a lifeline when he beat Hart with his free kick in the 87th minute to send the match into penalties.

Hart proved City's hero, with saves off Seydou Doumbia and Seydou Keita to get the English club home.