So I just finished Chapter I with quite a lot of frustration, doing my second playthrough of the game on hard. On my first playthrough (normal difficulty) the Beast got stunned right away and I killed him, piece of cake.

But this time I couldn't stun him at all, and after a few tries I gave up on that strategy. So I tried beating him without a one hit kill, but I find that impossible. I've got specter oil, tawny owl, swallow, blizzard. He just stuns me and half of my HP is gone by the time I recover, while I barely scratch him with my attacks. I tried that at least 5 times, failing miserably. I had to reload the game another 5-6 times until I got a stun on him with Aard and finally beat him.

Is this really intended? Am I missing something or is the only way to beat the Beast by stunning it with Aard? How could this not have been fixed after so many patches?

It's not been 'fixed' because it's not a bug.
It is argueable the hardest fight in the entire game but it does not require you to stun him in order to beat it, you can do it through ordinary combat but it is very, very difficult.

I can't offer any particular strategy for you but I know I defeated him with use of an upgraded Igni sign, it can catch all the foes in a single burst and set them on fire if you've upgraded that bit of the sign.

I just got here and died in seconds. I heard that the combat in this game was easy but I've accidentally wandered into several fights that seemed ridiculously hard so far. One was the plant monsters in a cave, another was the special drowner mini-boss and then this one. There's been a few other times where an encounter was just ridiculously hard, I died, reloaded it and then it was easy. I guess if luck doesn't go your way, you enter a slippery slope to death pretty quickly.

Edit
Okay so I loaded my save up from before the cutscenes and drank the vitality potion and applied the "do more damage to phantasms" oil to my sword. As soon as the fight started I hit F5 to quicksave (there's just enough time before the fight technically starts) and then just hit the Beast a few times and he died. All the other enemies disappear with him.

The peasant fight afterwards was pretty easy but at the end I felt bad about saying the more negative response to Abigail, so I loaded up the quicksave. The Beast fight was just as easy but this time the peasant fight seemed to glitch so I was stuck in "friendly mode" while the peasant killed Abigail and then the "We're gonna get you!" cutscene played so I could finally kill them. This time they all ran away from me and didn't attack, it took me ages to find the reverend. Fortunately at the end, Abigail comes back to life.

What do you mean you hit it a few times and it died? Did you stun it with Aard? When I hit it I barely do any damage (with the oil).

Oh, I should have specified that I'm playing it on Normal. It would actually have made my first post make more sense since my point was meant to be "I'd hate to see how hard this bastard is on Hard mode".

It does seem quite a lot based on luck, though. The third time I did it, all the enemies went for Abigail which made it easy. You could try hitting F5 at the start of the battle (just hammer it when the cutscene ends) if you haven't already done that. It certainly makes it less frustrating to try different things out.

Hard mode is easy compared to playing on Hard with FCR mod and its a wicked fight(every end boss is). The luck reference is true cause the combat engine seems ahead of the animations.(lose health even before cut scene ends). I got caught with the quick-save snafu though; it saved when I had only 10% health so the fight was futile..had to reload from way earlier time.

Another tip from another thread said to tone down all the graphic settings befor Boss fights(better FPS) so that you don't lose as much advantage. I have noticed that reloads of saves cost you in responce time..Always better the first time ;)

I started my second playthrough on normal with flash mod. I did every possible quest and sidequest before the end of chapter 1. When I encountered the Beast, it was so ridiculously impossible to fight it, that I started to laugh. First of all, effects of all my potions taken in the cave before the fight would disappear on the start of the fight - tried many times, always disappeared - so I had to drink potions after the fight started.
There were five-six barghest which would surround me and kill in seconds (despite drinking the usual potions for health, etc), or the beast would stun me and kill immediately.

I restarted this fight a dozen times, I was finally about to give up completely when I miraculously stunned the beast and killed it with one hit.

As much as I love the Witcher, I think this fight is completely crazy, unbalanced and unfair.

You are using the Flash mod!!!!! It gets worst like Chapter 2's fight at the Tower and then wait till you try to kill the King of the Wild Hunt in the epilogue IF your using the FCR mod!!

I'm no great gamer but their is always a trick/stratergy to get thru the fights/ quirks of the game ex: The end of the prologue at chapter 1 when you run into your first barghest hounds, just run towards the stockade door up the ramp and let them come after you one by one simple!

Your decision for Flash mod will force you from playing with the same old technique you acquired thru the "normal" game mode.

At least you laughed because of the difficulty of some fights; I used every french word I ever knew and pulled the plug on the computer to teach it a lesson for not doing what I envisioned it should do!!! Bad Computer

I'm gonna try FCR on Insane, bet I save a gazillion times though.

The Beast fight is annoying because it's about a hundred times harder than anything else in the game up to that point, and incredibly painful because it doesn't let you save beforehand so if you die you have to go through all the dialog and cutscenes again to get another try. I can only wonder what idiot came up with that idea.

In the end I only managed to kill it by stunning it and getting in a one-shot kill. I died every other time because I'd get stunned and they'd kill me.

Really, really awful design that almost made me quit the game at that point.

I LOVED THAT FIGHT. I played it on hard, as well, and I was impressed at how difficult it was. I, too, was unable to stun the beast. For me, it came down to using the Swallow, and retreating when I was getting beaten.

I agree that you should have been able to save AFTER that cutscene, though. It took me ~4 tries to beat the Beast, and I got sick of that cutscene.

You can save if you quickly press F5 or go into the menu. I've noticed that a lot of western RPGs that deposit you in a non-save situation actually have a small window where you can save as the battle properly triggers (Dragon Age does it too).

That fight is awful, took me about 10 tries on normal and I think it's completely unbalanced. Abigail always get knocked down, no matter what, those demon dogs keep spawning and the Beast is stunning every few hits. I managed to kill it by running around and at some point Abigail got revived (no idea how) she healed me and I could stun the Beast and kill it. The frustration after few tries nearly made me quit the game.

bad thing is that all the potion effects dissapear, if this was intended then it's a bad design decision. Good thing is that the oils stay on swords so at least you can go with one thing preset. As soon as the fight starts I hit a pause button and then drink swallow. After the animation is over, i drink blizzard and start hitting them with group fighting style, trying to occupy them all at once. As soon as there is only one or 2 lesser beasts, i switch to strong and concentrate on hellhound. It was by chance that I didn't upgrade my Aard so I couldn't stun him at all so I had to finish the fight using normal combat.
If you manage to make them all attack you, Abigail can heal you and 5 times out of 10 you'll win it. IMHO if you don't upgrade aard, it's just dumb luck if you survive or not. :(

Aside from what dr.zli just told you, don't be ashamed to pause the game and grab a bite to eat, drink some water, or some milk, or juice, or what have you. Now, I didn't have the flash mod installed, but, even if I had upgraded my Aard, I didn't want to just hope I'd stun the Beast by chance; I just switched to group style when I got surrounded, hit the blighters with every bit of Igni I could muster (hope you've invested some points in it, it helps tremendously) and took advantage of every window of opportunity to run around, thus allowing Geralt's healing capabilities to kick in.

Oh, don't sit back and relax after you've beaten the blasted thing, either; I'm not saying anything more, but you might just need to fight something else. Think about sharpening your sword with a Grindstone, too, if you can; I had several by the time I fought the Beast.

I usually just use a Blizzard potion at the beginning of the fight, then protect Abigail so she can heal. Kite a little until Abigail casts again if things get touchy.