Gagner is the infinitive, i.e., "to win". If you are using a verb in a sentence, the verb has to match the subject. The subject of the sentence is notre équipe. This is third person singular, which is why you also need third person singular of the verb gagner, i.e., gagne.

Our team wins. -- Notre équipe gagne.

Hi Mitchell,

"notre" is the possessive adjective and "équipe" is in the third person singular for conjugation purposes.

So we can say "our team win" gagne or "our team won" gagné

The conjugation is on the "team - équipe" not the possessive adjective "notre"

Bonne continuation

Jim

In English it would be "our team wins." The team is the subject of the sentence and "wins" is in the 3rd person singular just like team is. 

In French it is the same. Our is just an adjective that describes team, and the verb matches the word team. 3rd person singular.