僕はダブルスのトーナメントでブレンドンと組んだ。

。

I teamed up with Brendan in the doubles tournament.

Literal

I [topic-は] doubles [of-の] tournament [in-で] Brendon [with-と] paired.

組む in the context of people means 'to team up, to pair with.' The と here is the conjunctive 'with' that marks a co-participant, not the quotative. Note how Japanese renders the English name ブレンドン in katakana — standard for any non-Japanese proper noun.