The Order of the Stick: Vaarsuvius gives one of these to the ancient black dragon after accepting the soul splice. Given the level of power demonstrated immediately after killing her, it's obvious that Vaarsuvius could have just done a One-Hit Kill, but went for a slightly longer but equally decisive victory. Comics # 652 and # 653 pull a complete reversal: Vaarsuvius is so pumped up after the first battle that the elf decides to take the fight directly to the Big Bad Xykon with the soul splice's "Ultimate Arcane Power". Several rounds later, Xykon manages to literally beat the power out of Vaarsuvius.
The fight between Roy and Xykon is an straigther example.
Narrator: We were going to dedicate a full Sunday comic to the epic battle, but it's Bun-Bun against a turkey!Come on, people!
Sillice vs. Yaeminira/Vy'chriel in Drowtalesgoes like this. It's pretty obvious that Yaeminira never had a chance, and extra points for the implied Punctuated Pounding Sillice gives Yaeminira:
Sillice Focus, Will, Discipline, Loyalty!
In Circus Knights, there's a lot of build-up to how Domino and Talon have to take down a "Rook Level" Nightmare. The Nightmare reveals its true form, the battle begins, and what do we get? Talon and Domino impaling the souls off screen, Talon distracting it with shadow dolls, and then Domino cuts the Nightmare in half with something that basically amounts to a magical piece of paper
In Fans!, there is the last battle between the Fans and the FIB. What should have been a curb-stomp battle the other way around is reversed when a literal Deus Ex Machina turns it into one of the most one-sided battles ever, resulting in this: http://www.faans.com/index.php?p=1290
If the stories are true, Liu Feng from How I Killed Your Master did nothing else. He described his experience as "I don't know what it's like to hit a man twice."
Homestuck has lots of these. Let's enumerate, shall we?
Dave still manages to maintain his Badass status after verbally curbstomping Tavros (aka adiosToreador) in a reverse-trolling of epic proportions later in the series. (Technically in a flashback, but whatever.)
The showdown between Vriska, Gamzee and Eridan. The winner? None of them. Kanaya turns up in all her rainbow-drinker glory and wipes the floor with all three.
The long awaited battle between Vriska and Tavros. Vriska slaps Tavros in the face then runs him through with his own lance.
After defeating a whole bridge full of Imps, you'd think Vriska would be strong enough to fight Aradia, right? You'd be wrong.
Anyone versus BecNoir- Bro, Davesprite, John, Rose, Dave, a thousand Aradiabots- ends with them getting crushed. The only exceptions so far have been God-tier Vriska rolling straight 8s on her dice (which didn't count anyway because it was in a doomed timeline) and Prospitian Monarch, who has the exact same powers as Jack and is really pissed to boot.
Jake fights Dirk's training robot. The fight includes the robot slicing bullets in half in midair, performing a rocket-assisted suplex, and punching him so hard that his glasses fly off taking his eyes with them.
Dirk's rap-battle with Squarewave can hardly even be called a battle, as it is finished in only two attacks (by the same party) and the first didn't do anything. It's not even clear when Squarewave was supposed to get a chance to act.
Girl Genius has a Curb Stomp battle during the defense of Mechanicsburg. And immediatly after as well, both performed by Gilgamesh Wulfenbach. We never knew he had it in him... oh wait, yes we did, just nobody else did.
Jäger generals are even more dangerous than they look. Good thing (for them), there's always someone willing to learn this the hard way.
Kid Radd has Radd deal one to Gnarl late in the comic, to show Gnarl how he's bettered himself while Gnarl has been stuck as a slave to his programming.
