His hat-trick helped Pep Guardiola’s side to a 4-0 win and the perfect start to European campaign.
Kelechi Iheanacho completed the rout.
It didn’t go so well for fellow Premier League side Tottenham Hotspur who lost 2-1 to Monaco in their first match in Group E at Wembley.
Bernardo Silva and Thomas Lemar hit the mark for the French club in 15 first-half minutes and although Toby Alderweireld pulled one back Spurs couldn’t find the equalizer.
Elsewhere in the group Bayer Leverkusen and CSKA Moscow drew 2-2.
Defending champions Real Madrid got their title defence off to a nervous but winning start beating Sporting 2-1.
Bruno Cesar opened up the scoring, Cristiano Ronaldo levelled against his childhood club late on but Morata snatched the three points in stoppage time.
Also in Group F Borussia Dortmund welcomed Legia Warszawa back to the competition after 20 years with a 6-0 thumping of the Polish side.
Claudio Ranieri’s reigning Premier League champions Leicester City got their debut campaign in the competition off to a flying start beating Club Brugge 3-0.
Riyad Mahrez scored a brace of goals after Marc Albrighton’s 5th minute opener.
Champions League regulars FC Porto were held to a 1-1 draw by FC Copenhagen to complete Group G’s first round of matches.
Meanwhile in Turin, two-time European champions Juventus played out a goalless stalemate with three-time reigning Europa League winners Sevilla in Group H.
Lyon enjoyed a memorable Champions League opener in their new stadium – they comfortably saw off the challenge of Dynamo Zagreb 3-0. (Euronews)