I played with two people. One about same IQ as me, maybe slightly lower but having extensive experience (at least in comparison to mine) in chess (he played a lot as a kid, I played maybe 100 games total, never with significantly better opponent).
Second guy I played was more intelligent then me but had almost no experience in chess (he was incredible mathematician, transition between two lines of his proof that he saw obvious, required whole page of my reasoning for me to be understood, he represented my country in International Mathematical Olympics, he got master degree one year ahead of time).
With the first guy I won exactly once. Before that I lost about 20-30 games with him. When I played the other guy I was astonished how dumb moves he made. I won with him effortlessly first time.