Who beat God?

 Judges 1: ¹⁹ And the Lord was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron.

On Youtube there was an anti christian cartoon depicting this verse.  It would appear from first glance that God almighty had defeated an army. Yet then suddenly in His omnipotence He failed to accomplish his goal because of the chariots of Iron. As a result they showed a comedy and implied that the whole account was simply the jews using superstition to interpret the account.
  This however can be easily refuted if we will remember to take passages according to their context.  We must remember that the Bible wasn't broken down into verse division when first penned.

Judges 1
¹⁷ And Judah went with Simeon his brother, and they slew the Canaanites that inhabited Zephath, and utterly destroyed it. And the name of the city was called Hormah.
 ¹⁸ Also Judah took Gaza with the coast thereof, and Askelon with the coast thereof, and Ekron with the coast thereof.
 ¹⁹ And the Lord was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron.
  One common metaphor when reading Old Testament literature is that tribes are often given the personal attributes of their patriarch.  As we see the two tribes are spoken of the original two brothers in verse 17.  (simeon and Judah) 
  We also see from verse 18 that Judah in a military invasion is the subject of the text.  Therefore we can apply this understanding to verse 19.
So when it says "he", it would appear that this is referring to judah. Which had some victory but was stopped by the iron chariots.  Also the fact that "he" is lowercased instead of "He" for the LORD is yet another clue that this passage is not discussing the LORD in Battle but the tribe of Judah.