Pep Guardiola's Manchester City career got off to a winning start as they beat Sunderland 2-1 on Saturday but the Spaniard knows there is much work to do to build a title-winning team.
Paddy McNair's late own goal gave the hosts victory on the opening day of the Premier League season after Jermain Defoe's Sunderland strike had cancelled out Sergio Aguero's early penalty.
City dominated possession but were short on the incisive attacking play that was a hallmark of Guardiola's Barcelona and Bayern Munich teams.
"Sometimes you are a little lucky," City's new manager told reporters. "We should have been a bit more aggressive but these kind of things have to happen to know how to get better in the next game."
The match was an intriguing glimpse into what the fans can expect from Guardiola.
He showed his ruthlessness by dropping England goalkeeper Joe Hart to the bench and completely omitting Ivory Coast midfielder Yaya Toure.
"They are professionals," Guardiola said, "and are going to fight for their places."
He acknowledged it would take time for City to adapt to his methods although there was evidence of a new approach.
Captain David Silva started in a deeper midfield role from where he was expected to instigate attacking moves while the full backs came inside to congest the middle, in a similar way to Bayern under Guardiola.
"I'm very pleased about the performance," said the manager. "The second half we played really well.
"Maybe we should attack quicker. We have to learn."