Several years ago I stopped on a summer trip to camp/hike in the Three Sisters Wilderness Area in Oregon. Next to the primitive campsites was a large grassy field with a small stream passing through it. I was watching several mule deer grazing near the middle of the field when I saw a couple of coyotes take note and begin pacing the edge of the field. They didn't seem to have a good game plan, but the mule deer simply took note and continued grazing. I watched one of the coyotes make a run at one of the mule deer, but much to my surprise, the mule deer turned and ran directly at the coyote, sending it back to the edge. The third time the coyote tried this stunt got the muley really agitated, whereupon I watched the muley turn and chase the coyote (tail between it's legs) for a good 1/4 mile across the field until it was obvious to the muley that the coyote got the message. The coyotes never reappeared that evening.

Not sure how often this happens in the wild, but I imagine it's not rare.