in is correct. It emphasizes the time during which the match took place.
at is correct. It emphasizes the place where the match was held -- or the mere occasion of the match.
I believe that in most cases I would instinctively use:
at the [match / game / meeting / (family) reunion / party /
concert / performance / play / recital / lecture / (poetry) reading / (political) convention / (wedding) reception]
CJ