"Plegó alguna vela" Folded one of the sails (He's using the metaphor of a boat here for the team)
"Enfilaba el horizonte" Was pointing to the horizon (Again like a boat)
"marró la sentencia" He (the team) got the sentence wrong.
Basically is a fancy way of saying the team was so sure they were going to win, they were already thinking about the next game and that's why they messed up.
Hope this helps. Saludos!