The 30-year-old (below), a surprise summer signing from Manchester United, opened the scoring with his first goal since April 2008, locating the top corner from 25 yards just 17 minutes into his Etihad Stadium bow.
Mario Balotelli secured the win seven minutes before the break with his first goal of the season in front of just over 25,000 fans.
Meanwhile, Craig Bellamy struck his first goal for Liverpool since returning to the club last month in a 2-1 win over Brighton, which featured Steven Gerrard’s own comeback from a six-month injury lay-off.
Merseyside rivals Everton required extra-time to beat fellow Premier League side West Brom 2-1 at Goodison Park – Phil Neville getting the winner in the 103rd minute.
Championship high-flyers Southampton won 2-1 at home to Preston, while Cardiff beat Leicester 7-6 on penalties after a 2-2 draw.