Raheem Sterling scored just three minutes into his Manchester City debut but his new club needed penalty shootout heroics from Joe Hart to beat Roma after a 2-2 friendly draw.
The build-up to Tuesday's International Champions Cup match in Melbourne was predictably dominated by City's new record signing, and he delivered immediately with a cool finish.
But, after stunning strikes from Miralem Pjanic and Adem Ljajic sandwiched a goal from City's Kelechi Iheanacho, the Premier League side needed penalties to win.
Hart delivered in the shootout, scoring his own spot-kick before saving Seydou Doumbia and Seydou Keita's efforts to give City a 5-4 victory.
But soon after, the 20-year-old showed why City were so keen to secure his signature, as he slotted calmly into the bottom-right corner in a one-on-one with Morgan De Sanctis after being played in by Iheanacho.
Roma levelled eight minutes in, as Pjanic unleashed a long-range rocket that gave Willy Caballero no chance, before David Silva - central to most of City's best moments before he was withdrawn at the interval - forced De Sanctis into a top save.
Silva also picked out Iheanacho in the 33rd minute but the latter's header was straight at De Sanctis before Roma finished the half stronger - two cut-backs forcing desperate clearances before Daniele De Rossi's header went just over the bar.
But it was City who hit the front early in the second period, as Iheanacho got the goal his performance deserved, with former Chelsea and Arsenal full-back Ashley Cole inadvertently providing the assist.
The relatively sparse crowd inside the cavernous MCG had to wait until the 87th minute for another goal, with Ljajic beating Hart from 20 yards from a free-kick, before the England goalkeeper decided the contest in the shootout.
