BELGRADE-- Manchester City academy graduate Micah Hamilton scored on his senior debut as the side stretched their unbeaten run in Europe to 20 games with a 3-2 Champions League victory over Red Star Belgrade in their group-stage finale on Wednesday. Oscar Bobb also netted his first goal for the senior side and Kalvin Phillips scored from a penalty for City, who finished with a perfect 18 points from six group games for the first time. They joined Liverpool as the only other English team in history to win all six Champions League group games. Hwang In-beom and Aleksandar Katai netted late second-half goals at the Rajko Mitic Stadium for Belgrade, who finished bottom of Group G with one point. The 20-year-old Hamilton, who joined City at the age of nine, netted in the 19th minute when he cut around a Belgrade defender then fired from a tight angle into the far corner. Bobb, who is also 20, doubled the lead in the 62nd minute when he dribbled at the Red Star defence before tucking a shot into the bottom corner. In a game that meant little to City and nothing to the Group G standings, manager Pep Guardiola made nine changes to the side who played in the 2-1 Premier League win at Luton Town on Sunday. City's league-leading scorer Erling Haaland did not play at Luton due to a foot injury and did not travel to Belgrade. But on a terrific night for City's academy programme, young strikers Hamilton and Bobb filled in admirably in Haaland's absence. Outclassed in the first half, Belgrade made things interesting in the second to the delight of the raucous crowd who barely stopped singing all night. City keeper Stefan Ortego was forced to make two terrific saves shortly after the break before Hwang pulled one back in the 76th minute and Katai scored in injury time.