CHICAGO -- Mario Gotze's first-half penalty proved the difference as Borussia Dortmund kicked off the International Champions Cup with a 1-0 victory over Premier League champions Manchester City.
City's record signing Riyad Mahrez made his debut following his £60 million move from Leicester City and almost grabbed his first goal with a wicked free kick just before half-time. His 20-yard strike deflected off Sebastian Rode only for Dortmund keeper Marwin Hitz to brilliantly tip the ball over the bar.
Pep Guardiola was forced to field a makeshift line-up with plenty of youngsters and players who spent last season out on loan, with 16 senior players still to join up for preseason after playing at the World Cup.
Former New York City FC striker Jack Harrison also made his first start for City but it was Dortmund's United States international Christian Pulisic, back on home soil, who was biggest threat in a first half of few chances.
He was twice chopped down by Oleksander Zinchekno in the opening quarter of an hour before starting a quick break that created the first shot on target for Gotze, but his stinging effort was comfortably saved by Claudio Bravo.
The Germany international did break the deadlock with a 26th minute penalty. Pulisic won the spot-kick when he again caused problems down the right-hand side and was tripped by a clumsy challenge from Zinchenko.
Joe Hart came on at half-time for his first City appearance since August 2016 and was relieved to see a Mahmoud Dahoud strike drift inches wide of his post in the 49th minute.
Former City youngster Jadon Sancho, who joined Dortmund last summer, and his quick feet set up another chance for Dahoud, which Hart beat away.