With the world's most expensive player Gareth Bale on the home bench, goals from Filip Djordjevic, Aleksandar Kolarov and Lazar Markovic gave Serbia a victory that sends Wales to the bottom of Group A.
While manager Coleman pointed out that the Dragons, who were also missing captain Ashley Williams, were understrength, he conceded that his side could not match their opponents in any department.
"We were just outclassed," Coleman admitted to Sky Sports News. "Even if we were at our strongest, we're going in against a team like that where they're a good team.
"There is not a weakness in their play. They're strong and aggressive and even with the ball our game plan was just to try and stay in the game.
"We couldn't overlap like we normally do because we were not at our strongest going into the game. We just tried to stay in the game and the goals we conceded were not good goals at all."
Real Madrid's £85m signing Bale came on as a second-half substitute for Wales, who have picked up six points from their eight qualifying matches.