There is still a margin for a suprise

Panama have better fans than players! The way they celebrated their team's goal against England was at least impressive, despite the fact that they had conceded 6 goals earlier. Veteran defender Baloy surely became a national hero for his country. From then on, any set piece caused panic in Panama's defense and 6-1 was eventually honorable, since in the second half they managed not to be defeated (1-1) after the disastrous first half where they conceded 5 goals.

Tunisia needed only a win against Belgium and didn't concatrate in their defense. The final score 2-5 came naturally, as Belgian's offensive play caused panic in African's defense. Two of their defenders Bronn and Ben aren't playing in their last game of the tournament due to injuries. 

Tunisia are definitely a better team, but Panama's players seem to enjoy more participating in the tournament. There is some space for a surprise here, as the game quite indifferent for both teams. Thats why I expect a fairly open game. My call is Panama's win in the half, as I think that with the enthusiasm and the ignorance of the risk that their players have, they could take the lead and may keep it at least for the first half.