I think the Battle of Isandhlwana in 1879, between the Zulus and the invading British, could qualify. Here's a brief summary (you can decide for yourself whether it's worth pursuing further): The Zulu army took full advantage of the aggressive and overconfident (arrogant, really) nature of their opponents by using small clusters of troops to provoke the British into dividing their forces. These decoys used their superior mobility and knowledge of the broken terrain to appear and disappear without warning, completely confusing the British commander, who in his eagerness to join with the enemy, gladly mistook the small raiding parties to the south for the entire Zulu army (which was actually to the NE) and rushed after them with half his forces. Naturally the Zulu decoys melted away into the hills after leading the British a full day's march away from their base camp, and the real Zulu army then descended on the remaining British forces at Isandhlwana and completely destroyed them.
I suppose Isandhlwana is not a perfect example of divide and conquer for at least a couple of reasons. First, because the Zulus did not follow the maxim to its natural conclusion by going on to wipe out the second half of the British force (the part that had been lured away). But that was mostly due to cultural, not military, reasons--after any victory Zulu armies always dissolved and the men returned to their villages. And second, because the defending British at Isandhlwana made many more mistakes that contributed to their demise, so it is very possible that the divided troops could have held out anyway if not for those other poor decisions by their leadership.
Still, if you need a secondary example of divide & conquer Isandhlwana should serve since the victory would never have been possible without the successful use of that strategy. And it is also a very interesting and historically significant battle in its own right, being the worst defeat ever suffered by a modern army at the hands of indigenous forces.