Bento saw his side enter the interval trailing 3-0 and down to 10 men after Pepe headbutted the outstanding Thomas Muller.
Muller finished with three goals – Mats Hummels scored the other – and their woes were compounded by defender Fabio Coentrao's injury.
Coentrao was taken off on a stretcher with a suspected groin injury in the second half on a disastrous night for Portugal.
And Bento acknowledged his side were merely trying to restrict the damage after the break.
"The game is over in the first half," Bento is quoted as saying by Ojogo .
"In the second half there is little to add. (We were) trying to manage in the best way (with) the numerical inferiority.
"The second half of the game summed (that) up. The first five minutes (of the second half) we were not good. We were then able to balance.
"Until 1-0 (it) was a balanced game."
