Ultimately UFC 156 emerged as a night of upsets, and nowhere was that more evident than the top of the card at the Mandalay Bay Events Center in Las Vegas, NV on Saturday.

Antonio Silva stunned the mixed martial arts world, crumbling Alistair Overeem with a third-round blitzkrieg to take the early lead in 2013's "Knockout of the Year" running. Antonio Rogerio Nogueira turned back the clock, outpointing a suddenly listless Rashad Evans en route to a unanimous decision win. And to top it all off, former UFC lightweight champion Frankie Edgar and reigning UFC featherweight champion Jose Aldo engaged in a grueling, back-and-forth five-round struggle.

In the end Aldo retained his crown, claiming victory on the judges' scorecards, 48-47 and 49-46 (x2). However, like many of Edgar's past bouts, the ruling was not without controversy.

I got it 2 1/2 to 2 1/2 damage Aldo, both legends! — Luke Rockhold (@LukeRockhold) February 3, 2013

I think Aldo 1 and 2... Frankie 3, 4 and 5. Agree? — Joe Lauzon (@JoeLauzon) February 3, 2013

there should have been a new feather weight champion. frankie edgar is still my hero :) — Nam Phan (@NamPhanMMA) February 3, 2013

I could watch Edgar and Aldo fight about a million more times and still be happy. #UFC156 — Tim Kennedy (@TimKennedyMMA) February 3, 2013

I am stunned that people are stunned that jose won that fight. To be the champ you better beat the champ n that did not happen — Jens Pulver (@Jens_Pulver) February 3, 2013

This could be 2-2! Would have never thought that could happen after the 1st round — Dana White (@danawhite) February 3, 2013

Joe Rogan could have you thinking that the person who is losing the fight , is winning the fight ! #UFC156 — Derek Brunson (@DerekBrunsonMMA) February 3, 2013

That front kick has dropped many a fighters...damn Edgar is tough — Sarah Kaufman (@mmasarah) February 3, 2013

Shame! @frankieedgar is the best fighter ever to lose his last 3 fights, but not really lose his last 3 fights. — Din Thomas (@DinThomas) February 3, 2013

Had Aldo winning that but Frankie Edgar is still my hero. Two legends went at it tonight in the main event. Awesome fight! #UFC156 — Kenny Florian (@kennyflorian) February 3, 2013

In my opinion Frankie won a very close fight. — Tom DeBlass (@TomDeBlass) February 3, 2013

@josealdojunior is great champion congrats bro — glover teixeira (@gloverteixeira) February 3, 2013

Great title fight. Saw Frankie winning 4 and maybe 5, but Aldo is a freak and is great at defending leg attacks. — The Aaron Simpson (@aaronsimpson) February 3, 2013

Am I the only one who thought @frankieedgar won the last 3 rds. I really thought Frankie won 48-47 @ufc @danawhite — Brock Jardine (@BrockJardine) February 3, 2013

Frankie didn't pull it off in the end but what a fight also judges who had it 49-46!? are crazy!! Frankie 100% had the last 2rounds #UFC156 — John Maguire (@MaguireTheOne) February 3, 2013

Franky wins the last two rounds, but Aldo did the most damage and should win the fight. 3-2 for Aldo #ufc156 — Nik Lentz Ufc mma (@NikLentz) February 3, 2013

The right guy won, but horrible score cards.....#ufc156 — Nik Lentz Ufc mma (@NikLentz) February 3, 2013

I have Aldo winning the first 3 rounds + the fight. Great fight. More importantly is #UFC156 the best card top to bottom ever?? — Kyle Kingsbury (@Kingsbu) February 3, 2013

Gotta go 48-47 Aldo but 3rd round was razor close — Steven Siler (@Stevesiler) February 3, 2013

Man Frankie is a warrior — Amir Sadollah (@amirMMA) February 3, 2013

NOGUEIRA OUTPOINTS EVANS

I had that fight 2 rds to 0 for Nog. Didn't count the first round cause it ABSOLUTELY SUCKED!!! — Dana White (@danawhite) February 3, 2013

If you could change Sugar Rashads nickname what would you change it too? Sugar free Rashad? @ufc — Ulysses Gomez (@uselessgomez) February 3, 2013

Interesting night for the Blackzilians — Jon Bones Jones (@JonnyBones) February 3, 2013

Not a great fight to watch between Rashad & Lil' Nog & it was super close but thought Rashad squeezed it out. #UFC156 — Kenny Florian (@kennyflorian) February 3, 2013

Great fight for minotouro — glover teixeira (@gloverteixeira) February 3, 2013

I wish instead of bouncing around Evans would just fight! Let them go! — Krzysztof Soszynski (@KSOSufc) February 3, 2013

Brazilian s cleaning up tonight. — jimi manuwa (@POSTERBOYJM) February 3, 2013

....I would say 29-28 Nog....possible draw #ufc156 — Nik Lentz Ufc mma (@NikLentz) February 3, 2013

Well that fight was a let down! #UFC156 — John Maguire (@MaguireTheOne) February 3, 2013

And the winner of lil nog vs @sugarashadevansis........Chris Weidman??? Lol #UFC156 — Steven Siler (@Stevesiler) February 3, 2013

Lets do this Anderson! — Chris Weidman (@ChrisWeidmanUFC) February 3, 2013

SILVA CRUSHES OVEREEM

Wow what a KO — Jon Bones Jones (@JonnyBones) February 3, 2013

There is nothing behind the words! — juniorcigano (@junior_cigano) February 3, 2013

WOW!!! Did I really just see that ?? — BrutalJohnnyBedford (@BrutalBedford) February 3, 2013

Somebody get Bigfoot a new hat haha that was awesome! — Luke Rockhold (@LukeRockhold) February 3, 2013

WOW!!! Pretty sure Bigfoot was asking Overeemhow u like them apples. #respect was just taken — Brock Jardine (@BrockJardine) February 3, 2013

Um.......Upset? Very few saw that happening. My God!!! — Pat Miletich (@patmiletich) February 3, 2013

Haha! "@scottiemc2: If jay Leno and tony Robbins had a kid he just knocked out overeem." — Ulysses Gomez (@uselessgomez) February 3, 2013

Upsets make UFC's! Huge K.O. by Bigfoot. TKO my ass! — Aaron Riley (@aaronrileymma) February 3, 2013

Referees tryin to let people die tonight. Better than stopping it early tho… #UFC156 — Jason High (@KCBanditMMA) February 3, 2013

Bigfoot over Overeem. RIGHT hands!! Dayyyyyum! Can't get cocky at any weight in the @ufc let alone at heavyweight. #UFC156 #upset — Kenny Florian (@kennyflorian) February 3, 2013

OH MY GOOOOOOOODDDDDD!!!! — Kyle Kingsbury (@Kingsbu) February 3, 2013

Holy shiiiiit! — chad mendes (@chadmendes) February 3, 2013

Cheaters never win . Good for you Antonio Silva #UFC156 told ya — Derek Brunson (@DerekBrunsonMMA) February 3, 2013

Holy #%^* Big Foot FTW!!!!!!!!! #ATT @americantopteam — Nik Lentz Ufc mma (@NikLentz) February 3, 2013

Mma is such as a genuine sport that it shows in its most pure form. — Raphael Assuncao (@RaphaAssuncao) February 3, 2013

Wow! Congrats silva didnt see that coming! — Scott jorgensen (@Scottjorgensen) February 3, 2013

That made me smile :) — Cub Swanson (@CubSwanson) February 3, 2013

Oooooohhhhhh shhhhhiiiiitttttt!!!!!! — jimi manuwa (@POSTERBOYJM) February 3, 2013

Wow the reem got knocked out standing up — roland delorme (@rolanddelorme1) February 3, 2013

Velasquez vs Dos santos 3!!! Let's do it UFC — juniorcigano (@junior_cigano) February 3, 2013