Backup bands

Assuming all or most of you have gone to concerts I was wondering have you ever gone to see a band you really wanted to see and then watched them get smoked by their backup band? Augsut 3, 1975, right before embarking to college we were lucky enough to score concert tickets at the providence Civic Center to see the band we all wanted to see: Black Sabbath. Very tough ticket at the time and we were pumped. They were ok, with a drunk Ozzy Osbourne, but their back up band fucking made them look like a high school band at a dance. Back up band actually did 3 encores. We were mesmerized and left the concert thinking that the back up band might make it big some day. They did better than that with their pyrotechnics, stage show and costumes/masks. Who were they? Kiss.