I missed the first half, alas, but saw most of the second, of Mexico's narrow win over Cameroon.
The first half was scoreless (I certainly wouldn't've guessed that), and the second was close.
Cameroon was playing a high-pressure defense, especially as the game wore on. They tried counterattacking, but it must be said that they weren't very good at it. They just couldn't maintain speed with the ball to get numbers. (Perhaps the heavy rain contributed to that.)
Mexico was much more methodical, and heavily dominated possession. They really only ended up with three good chances in the second half, though. The first, off a beautiful one-touch, outside-foot feed from Dos Santos, left one of the other forwards behind the defense. But his shot went right into the planted leg of the goalie and bounced all the way out the side of the pitch.
The second gave one of the forwards a shot in the middle of the box, with a bit of space, but the goalie managed to deflect it out. But a trailer on the play got that rebound and found the open net (and again we were treated to gratuitous usage of the goal line camera, despite the ball literally hitting the back of the net).
And the third was in the waning moments of the game, as a forward (#7, I think), forced a cameroonian defender all the way back to the touch line, and divested him of the ball in the corner. Chicharito had subbed in by this point, and was hanging out at the top of the box, in the middle. Undefended, for some reason. He stepped up, the other forward fed him the ball, and he tried to kick it on the full volley, putting it over the net (from only about five yards out). He had time and space; dunno why he couldn't do something better with it.
But the game stayed within reach for Cameroon, since only one of those made it in.
And they pressed and came close a couple times in the last several minutes, but were unable to put anything the goalie, putting Mexico in good shape to move on (but no guarantee; Croatia winning both their games would probably eliminate El Tri).