You know that meme that Lionel Messi isn't good for Argentina? It's unfounded. Alejandro Sabella and previous managers have struggled to put pieces around him that combine well with him, but he might have finally found the winning formula. Messi is one of two attacking midfielders with creative roles in Argentina's team against Ecuador, playing alongside Angel Di Maria in a 4-2-2-2 behind two strikers and in front of two holding midfielders. It's working brilliantly, and the Albiceleste lead 3-0 at halftime.
Sergio Aguero found the breakthrough in the 20th minute, finishing off a great move. Messi started it with a pass to Di Maria, who hit a great through ball to Aguero. The Manchester City man finished from the narrow angle to take the pressure off Argentina. From then until the end of the half, they began to play more loosely, and that loose play created two more goals.
Messi set up Gonzalo Higuain for a goal with a through ball in the 30th minute, then scored one of his own a minute later. After a long run through the middle, Messi laid off the ball for Higuain at the top of the box, and he quickly returned the ball to Messi, who finished.
At this point, Ecuador are basically in damage control mode. There's almost certainly no way back into this match for them.