The Imps fell to their first defeat of the season at high-flying Peterborough United, who showed why they are favourites for promotion.
Braces from Jack Marriott and Jonson Clarke-Harris proved enough for Posh to claim all three points in the August sunshine.
Although City were beaten on the day, the travelling fans showed their appreciation by applauding the players as they showed their thanks for the incredible backing on the day.
Attendance: 9,040 (1,633 away).