Celtic edged out Manchester City 4-3 in a seven-goal thriller on Tuesday. (More Football News)
City won the Premier League title last season, retaining the crown for a fourth season running, but they were undone by the reigning Scottish champions in North Carolina.
Erling Haaland captained Pep Guardiola's team, and his header dragged City level after Celtic had taken a 3-1 lead by the interval.
Nicolas Kuhn scored twice for the Bhoys in the opening 45 minutes, either side of Oscar Bobb's effort, with Kyogo Furuhashi also getting in on the act for Celtic.
Bobb teed up Maximo Perrone to reduce the arrears before the Norwegian youngster supplied the cross for his compatriot Haaland to head home a City equaliser in the 57th minute.
But the day belonged to Celtic as, 11 minutes later, Luis Palma grabbed their fourth to seal a memorable friendly victory for Brendan Rodgers' side.
Data Debrief: City's leaky defence
For all their attacking talent, City's success under Guardiola has been built on solid foundations, but in the absence of first-team like Ruben Dias, John Stones, Manuel Akanji Nathan Ake and Kyle Walker, their inexperienced back line failed to cope with Celtic's attackers.
City allowed 13 shots, but they accounted for 2.4 expected goals, while Guardiola's side accumulated only 1.7 xG from 16 shots going the other way.
Celtic created five big chances, and Guardiola will want to see improvement in that defensive solidity as pre-season progresses.
