Wait a second, that WORKED?!

[Arkonnan]

mine was in kingdom hearts: birth by sleep on the secret boss Vanitas remnant. Normally, this guy is crazy hard, so I hid. Guess what: his AI can't cope with obstacles so he ran around on the other side of the rock. Meanwhile, I had figured out that if you lock on, your strike raid attack will pass through the rock and hit him. So one of the hardest boss fights ever became easy (if not overlong, as strike raid does little damage).

 

[Oilerfan92]

In Resident Evil 4 I was fighting some guy in a burning barn or something. I used all my ammo, and my regular grenades. All I had left was a single incendiary grenade, which I had never used before. I blindly threw it at the boss and BOOM. He died.

 

[Tim_Buoy]

shooting wesker with an rpg in resident evil 5 we had been fighting him for 2 hours when we ran out of ammo on the 6th try we tried it and killed him

 

[ChocoFace]

a flying boss in borderlands that threw firey balls on death at me every second. took only a few to kill me.
Then i accidentally switched the car's weapon from rocket launcher to machine gun and killed the boss in 4 minutes flat. Sometimes i hate and love myself equally at the same time.

 

[Reed Spacer]

Venus, Final Fantasy Legend II.

I accidentally hit her with a stone spell.

It worked.

 

[Twilightruler]

Last boss in Assassins Creed 1, final fight. You and the leader in the courtyard. As soon as the fight started I just sprinted straight towards him and held the tackle button. I knocked him over, hidden blade, done. I was laughing so hard I started tearing up.

Also, final boss in Ninja Gaiden 1. First try I failed. Second try I realized you could just chain Flying Swallows and the amount of time before he recovers from it is just longer than the amount of time it takes to get the move off. Stun-locked him down with Flying Swallows. But then I beat him regularly on my Hard play-through to make up for being an ass and feeling like I missed out on something.

 

[michael_ab]

Anyone remember the dragon near Andrastes tomb in Dragon Age: Origins? Some say its an insanely hard battle, well I dont really think so. For some reason the dragon got stuck in a pillar and couldnt move, but it could still attack if I got close. So I just pulled my melee characters away from it and blasted it with arrows and magic from a distance. Seemed pretty easy to me

I remember that one. It was sorta fitting for this topic. My character was an archer. I pumped him full of fire resist, and stood at the perfect range, where it just shot fire attacks at me and then had a healer heal him from outside the blast radius.

It took forever, but was a very simple strategy.

everyones talking about these dragons... i always play a damage mage, just hit it with affliction, vulnerability, and paralysis. then just hit it with all the cold and lightning you got... over and over. if he gets up, cast a glyph of repulsion, then a glyph of paralysis on top of it, and hell be paralyzed again. switch between those 2 and you have a dragon that cant do shit

 

[Laurie Barnes]

Devil May Cry 3
Beowulf, a towering juggernaut that has insanely cheap attacks, a fuckton of armor, and everything else described by the OP.

So how did I beat him? Well at one point he started throwing steel cages bigger than he was at me, and how did I fight back? Well in a moment of frustration addled rage I charged headlong at him in an attempt to best him before he could throw any more towers, and I accidentally collided with one, however instead of dying, the tower was thrown back at him and dropped a health powerup.

 

[Randomologist]

The mutant protopet in R&C 2 killed me twice when I was about to kill it, I returned to finish other worlds and bought the RYNO2. Never looked back.

I also managed to quickscope the two Russians in the Kirov Park level of Hitman 2, after having tried the sneaky route and both of them running away. Both headshots. Feels good, man.

 

[Veldel]

Pokemon Yellow

I took a Boulbasor that was was low level into the Final Gym for some reason Geovanis pokemon refused to use Damage type moves and I spent a good while whittling down there hp and killing em

 

[Kurokami]

Ridiculously Difficult Bosses. We've ALL had our share. You pick away at its monstrous health bar and try to dodge its ridiculously cheap attacks. Time after time, though, it curb stomps you American History X style. Then, it happens. In either a flash of genius or an accidental screwup, you find it. A cheap little trick. A stupid little tactic. Something simple. It completely wrecks his shit. You've completely destroyed this previously unstoppable juggernaut with a simple move. You have now facepalmed so hard you can feel the back of your skull.

What's your favourite "Wait a second, that WORKED?!" moment?

Mine is facing Jormungandr in Magicka. Giant snake, holds its head off the ground so you can't hit it until it's about to attack. I accidentally cast Grease on the ground in front of it, then set it on fire. It then proceeded to take off 7/8ths of its health bar by DIPPING ITS HEAD IN THE GREASE FIRE. Do that once more, and it's done.

It wasn't anything planned, but in Dark Messiah I was walking around that dark crypt when a Blood Cyclops thing snuck up on me (For my defense I was bullying some guy and didn't notice it till it was behind me) I responded by bravely retreating with a loud battle squeal. And it tripped over and died. No shit, the thing flipped over and died by itself. (It was right next to a drop area, so I guess it somehow glitched because it was too close)

 

[TheSquashedOrange]

Final boss of Twilight Princess. Basically, after whittling down Ganon's health during the sword duel, it gets to a point where you clash blades and have to mash A to strike him down for good. I initiated this sequence many, many times but always failed, and had to do it again each time. Finally, I got frustrated, and screamed at the screen "JUST FUCKING DIE YOU PIECE OF SHIT!" And flailed the Wiimote about whilst demolishing the button.

As it happens, you were supposed to be shaking the Wiimote to defeat him. And that's how I won.

...Wait, you can shake the Wiimote too? I've just been mashing the A button and it works for me. I need to try that sometime.
OT: My moment would have to be in Phantom Hourglass, where you had to imprint a mark on the top screen on to your map on the bottom screen for the second sea map. I must have tried a bunch a crap before I closed my ds to take a break. When I opened it back up, lo and behold, the deed was done. Was a rare moment where I was pissed and happy at the same time.

ARGH!!! I got stuck on that in Phantom Hourglass to! In the end I showed it to my brother after about an hour of swearing, and he figuired it out in five seconds, god that made me mad...

 

[Ironbeard]

Anyone remember the dragon near Andrastes tomb in Dragon Age: Origins? Some say its an insanely hard battle, well I dont really think so. For some reason the dragon got stuck in a pillar and couldnt move, but it could still attack if I got close. So I just pulled my melee characters away from it and blasted it with arrows and magic from a distance. Seemed pretty easy to me

When anything can seem pretty easy when it completely bugs out and the boss cant touch you.

Sure is. I guess I just got lucky that time. I had to

Spoiler

Fight Flemeth in her dragon form without any bugs

That one was pretty hard. Harder than the Archdemon

I somehow managed to be glitched umder the dragon, who then couldnt hit me but i coult hit her with morrigan

 

[Bender Rodriguez]

Bioshock, when i got to the last boss i was expecting multiple deaths.
Beat him on first try

 

[Mallefunction]

Mine wasn't a boss fight...but the Subject 16 puzzles in ACII. There was one picture matching puzzle that I COULD not figure out so I just began selecting combos at random. My first try...BAM, solved! XD

 

[Death God]

Hollister from Gun. I couldn't get close without him using his cutlass and killing me, I couldn't get too far away without him finding Fights-At-Dawn, and I couldn't stand still unless I wished to get bombarded with his TNT. Then I finally got behind a rock and sniped him to death. He didn't even move while I sniped him. I died 20 times and to find it was so easy made me SO. DAMN. ANGRY!

 

[Ultress]

When I was younger I always got stuck on the Pirahhna Plant boss in Yoshi's island. So figuring I was going to lose to him anyway just started shooting eggs off the wall,and end up hurting him. THugh looking back it was pretty obvious that's what I was supposed to do.

 

[Luftwaffles]

Bioshock, when i got to the last boss i was expecting multiple deaths.
Beat him on first try

Before taking the elevator i loaded up on Electric Gel. 3 rounds i watched him jitter around and then finally just plasmid him to death.

 

[Yopaz]

In Lufia II there was a secret boss that didn't have a max health limit so if you used a healing item on it it would loop and it would have almost no HP at all and you could kill it with 2 attacks... of course he was so strong he could do the same...
I just know this trick, I haven't actually used it... never found all the eggs.

 

[Mr Pantomime]

I had one in Kingdom Hearts, with Sephiroth. I was about level 45, and couldnt beat him, because, well, I was level 45. Then I realised not only does strike raid actually have multiple hits if timed right (I never even knew), but it makes you invincible. So I fought sephiroth, and whenever hed pull out something big, id strike raid and stay immune.