The match wasn't fair, it was obvious a hand ball. If Fluminense was able to equalize the points, the result might be different. Both Cucurella and Pedro plays big role, Cucurella saved Chelsea from goal by his clearance, Pedro score 2 goals, but they also get helped by referee.
Wasn't fair for what? The ball is hitting directly to the Chalobach's hand, and pretty obvious no intention from him to block the ball as he's in the natural position. So the decision to overturned it was right. Even the ref was also announcing it through his mic, and also add clarity regarding ref's decision to overturned it.