The game was marred by the behavior of some rowdy fans shouting and letting off fireworks in the stands.
Being on the flightpath to the international airport is the only factor that mars the peace and quiet of this neighbourhood.
When you don’t want to use the verb spoil, which itself has multiple meanings, the word mar is an effective synonym and is shorter than the somewhat ambiguous impair. To mar doesn’t seem to be that commonly used and may be more often found in written English.
The verb is a regular verb, so the past form is marred and it derives from Old English and Saxon verbs merran and merrian which meant to hinder or to waste.
Given that el mar is the sea in Spanish and il mare in Italian, perhaps some foreign speakers of English will find it a strange choice, since it has nothing to do with marine or maritime.