Umm... You plan on having a bloody big lump of meat charging through a street... A confined tunnel...
What you don't do is try and jump on the running thing with a spear..
You arrange for sturdy pointy sticks to suddenly appear in its path. Nicely set at an angle. Good against cavalry. Good against overgrown cows..
Not that hard, and part of any training our mighty "warrior" boy should have had..
But I'm expecting logic in my narrative again, am I... Stoopid Meh...