The International Champions Cup began its action in Chicago where Manchester City played Borussia Dortmund. Riyad Mahrez made his debut for his new club in the United States and Christian Pulisic, the American, started on home soil too. The English club started the match brilliantly and looked domineering in terms of possession.With a line-up filled with unfamiliar faces and many youths, it was a golden opportunity for Pep Guardiola to find out which youngsters he could keep by his side and play in the Premier League. Dortmund then grew stronger and pressed higher. The players started to identify the loopholes in the Manchester City team and picked out their mistakes. The first shot on target went to the Bundesliga club. Crowds roared because Pulisic delivered a fantastic cross for his team-mate prior to that shot.Zinchenko gave away a penalty in the 27th minute and Mario Gotze scored from the spot against Claudio Bravo. Again, Pulisic was the man who earnt the set-piece for his side and aided his team to get the lead. Isak had a chance to double the lead, but his shot went into the side-netting. The 19-year-old American star seemed to be truly enjoying himself with the chances that he has created for his team.Mahrez took an excellent free-kick in hope to bring the scoreline to 1-1. However, Marwin Hitz made an amazing reflex save to prevent his side from conceding just before half-time. Overall, the Premier League Champions seemed to be missing someone like Sergio Aguero who is capable of pulling off wonders in the box.Joe Hart took over the gloves after the break as he played for Manchester City once again after nearly two years. The English international's future at the club is currently looking bleak as Guardiola is keen to sell him on a permanent deal. On the other hand, Lucien Favre changed the whole team except the keeper at the start of the second half.The Citizens were ultimately unable to find the net as they lose their opener to Dortmund. Pulisic stole the show in the first 45 minutes and it was sufficient to help his team win the game. here was how Twitter reacted to the Champions losing the game to Dortmund.Jack Harrison is putting in some serious work right against Dortmund and I’m loving it!— Zachary Sietsma (@ZachZsietsma) July 21, 2018Pulisic is owning this man city dude. Gotze scores the penalty! #bvb #mncbvb— Tyler Scott Hess 🎅🏼 (@tylerscotthess) July 21, 2018City 1 nil down v Dortmund. Disgraceful. Can’t see Pep lasting until Xmas 😗— FELÉ (@VivaRedRom) July 21, 2018Pulisic just broke some dude’s ankles and drew a penalty. Soccer’s back.— Stars and Stripes FC (@StarsStripesFC) July 21, 2018Zinchenko will be having nightmares about Pulisic. The American is giving Oleks a hard time.— City Watch (@City_Watch) July 21, 2018Pulisic >>>>>>>>>>>> the world— ʟᴀᴜ ᴍᴏɴᴅʀᴀɢᴏɴ (@proudofreus) July 21, 2018Decent first half. Eric Garcia, Jack Harrison and Foden best so far imo. Zinchenko terrible. Mahrez is adjusting and almost scored an amazing free kick. Dortmund have been good.— ً (@GkRole) July 21, 2018I take great pleasure in the fact Pep Guardiola is currently weeping in the locker room pic.twitter.com/1lSu0YaEea— Luca (@FearTheKirch) July 21, 2018very young side did really well tonight. proud of the boys. on we go @ManCity— MCFCPip (@1985_phil) July 21, 2018It's 4am and I just wasted several hours and my whole sleeping schedule to see some kids lose to Dortmund 😍— Elias (@E2AFIFA) July 21, 2018What a performance! Very impressive. Other than that free kick City didn't really have any chances. Dortmund look great defensively.— BVB Network (@BVB_Network) July 21, 2018Man City 0-1 BVBGreat performance from BVB absolutely suffocated Man City during the first half and were very good in the second too. Jadon Sancho, the kid is a special talent. What a player.— usman (@usman_94_) July 21, 20182 shots on target for the entire game........pathetic.— Teddy The Tipster (@teddythetipster) July 21, 2018Meh! 1-0 to Dortmund,admittedly the better team,not really bothered,although I hate losing any game,but,am slightly worried about the team we'll be able to put out for the charity shield,or whatever it's called now.great to have 16 players at the world cup,but now we pay. #MCFC— MancSoMCFC 🐝 (@ManCandLovingIt) July 21, 2018Can all city players come back now, I’m getting worried bruv— Mr.Magic (@EBeleke) July 21, 2018Man City lost to Dortmund 😂#ManCityBVB— Rida (@HiighOnCoffee) July 21, 2018Perfect Morning never exist 😂 @ManCity @BVB #ICC pic.twitter.com/oMKF0fmo7C— Arśenalist. (@Lacaboomxhaka) July 21, 2018