The Thunder Kick (Yi wang da shu)

 Sometime in the early nineteenth century, A fisherman (Li Chin-Kun) gets into a fight with a bunch of ne'er do wells trying to charge for passage over a bridge. But as his disapproving mother tells him, violence has a way to escalate, and soon some revenge-hungry toll entrepreneurs turn up at his house with... oh shit! It's Bolo Yeung in a cool hat/open vest ensemble.
 The fisherman fights alongside a stranger who turned up to chat up his mom, and Bolo and the other goons are handily beat. Because they fought together, the stranger proclaims the fisherman his brother (battle brothers!) and ends up gifting the fisherman and his mom a fancy house. Way to undercut mom's pacifist message, stranger.

 I kept expecting the other shoe to drop, and the stranger to reveal some ulterior motives... and when he returns to his home city, he kind of does - but it's nothing nefarious. It turns out that he was apparently involved in a feud with a cartel led by three brothers, and that maybe he was scouting for bodyguards or something similar. Whatever it was he planned to do, we'll never know, because the nefarious triad gang up on him and punch the guts out of him (not literally, sadly) shortly after he gets back.

 But his plan does end up working, if posthumously: The fisherman soon heads to the city to visit his battle brother, learns of his demise, vows revenge... and then spends a pretty boring half hour or so watching the three evil brothers run their criminal empires. Eventually, he and some allies come up with a pretty clever plan - a Red Harvest-style scheme to set the brothers against each other so their organizations can be picked off one by one.

 And then, in the final thirty minutes or so, the fisherman does just that, going after each one of the three crime lords in some pretty cool, drawn out fights.

 I was a bit worried for a while there because the first few fights - including the Bolo one - are fairly weak; No one embarrasses themselves, but they're extremely unmemorable.
 Luckily the brawls towards the end are much much better and include some excellent bits of colour like people jumping into the fight from the floor above or getting thrown clear across some sliding doors. They have a strong sense of physicality, which is not always the case in these older kung-fu movies. The final confrontation, an excellent, prolonged one-on-one duel, is the only time weapons are drawn (a staff and a pair of tonfas). To my taste at least, it cinches the deal, and easily makes this movie worth a watch.

 Shame about the story - the bones of a good yarn are there, but director Wing-Cho-Yip fails to find an engaging way to tell it. It's also seriously hampered by a too-perfect protagonist who never is even remotely threatened by any of the fights he throws himself into, and doesn't have the sort of charisma to make his invulnerable character fun to watch. Hell, I only watched this a few days ago, and I'm struggling to remember the first thing about him. Except that he can swing a pair of tonfas really, really well.