It's not an impossible scenario, you just have to keep the right goal in mind. In a multiple attacker situation, forget about movie heroes beating down 6 guys and walking calmly away. You probably don't have a script and a stunt double like they do.
The key to defending against multiple attackers is in fighting only one at a time. Again, the purpose is to escape. Try to get one person in front of the others, and use him as a shield if you can. Gouge his eyes and elbow him in the head, and if he's more trouble than he's worth, shove him HARD into one of the others. Get any obstacle you can between you and them - car, table, waiter - anything. Anything that slows them down gives you more time to get away.
Next time - your Exit Strategy