I assume we are allowed to run through the crowd even if we can't blend in, which is good enough. The crowd would be a great asset in that instance. It is very difficult to fight in an actual crowd of people. Counters become a lot more effective.
If there was a hole in the crowd in which all of these people (I will assume 7 or 8) have free room to get me, then I will likely back myself up against the crowd. Ensures I can't get surrounded by combatants and slightly narrows the corridor of attack areas.
This whole scenario, however, is extremely stupid. The last place a gang would want to fight you is in a crowd. They really, really hate witnesses. A good gang will instead lure you into an alley or someplace like that. Someplace a bit more private. In that scenario, I would rely a lot on the surrounding environment and quick foot movement. Intimidation becomes a better strategy than pure fighting. And you'd better pray the gang doesn't have serious backup at that point. Sometimes the best strategy is just giving them what they want. Above all, you have to be as honorable as the gang is. These people gauge respect on specific levels. Some gangs will not bother fighters that aren't dirty. Some gangs will not bother very dirty fighters. The best way to get a gang off your back is to be on the same level as them. If they are aggressive and cheap, as the OP makes them out to be, they understand being treated in kind. They will respect an aggressive and cheap opponent, even if they still beat him.
Of course, all of this is dealing with gangs. Trained combatants is another matter entirely, and one that I know less about (mostly because I'm not in the military).