Erling Haaland scored twice on his Premier League debut as Manchester City beat West Ham 2-0 at London Stadium.
A first-half penalty from Haaland was followed by a typically clinical finish when the big-money signing after the break, as the champions picked up three points from their opening game.
With Haaland seen as the striker Pep Guardiola has been lacking since Sergio Aguero's departure, it was fitting that the new arrival became only the second City player to score a brace on his Premier League bow, with the former Argentina international being the other in August 2011.
Hammers boss David Moyes was forced to start full-back Ben Johnson at centre-back alongside Kurt Zouma, with Angelo Ogbonna, Issa Diop and new signing Nayef Aguerd all out injured.
It took a while for City to get going, and they thought they had taken the lead when a neat move down the left led to Haaland playing in Ilkay Gundogan, who squared for Kevin De Bruyne to sweep home, only for the offside flag to go up.
Moyes's injury problems mounted further as Lukasz Fabianski had to go off after taking a knock in a challenge for the ball with Haaland, Alphonse Areola replacing him.
One of Areola's first contributions was to bring down Haaland when he was through on goal to concede a 36th-minute penalty, which the Norway striker dispatched calmly, sending Areola the wrong way.
Declan Rice skied a presentable chance over after a Gundogan error early in the second half, and some uncharacteristic misplaced City passes crept in as the Hammers looked for an equaliser, turning to their own new striker Gianluca Scamacca to come on just before the hour.
Haaland struck again after 65 minutes, though, when a City counter-attack saw De Bruyne slide his new team-mate in and the former Borussia Dortmund man placed his shot coolly past Areola to seal the points.