The UFC lightweight division houses some of the sport's finest competitors and athletes.
Stacked from top to bottom, the 155-pound class lives in a state of persistent fluctuation, with the top 10 changing from event to event.
At UFC 165, two top-10 lightweights in Khabib Nurmagomedov and Pat Healy squared off, creating the opportunity for yet another shift of the rankings.
Let's see how the top 10 shakes down after this pivotal lightweight matchup from Saturday's event.
Is Nate Diaz still an elite lightweight?
Just two fights ago, many (including myself) thought Diaz was the man to steal Benson Henderson's championship strap. Yes, it was a bad matchup on paper for Diaz, but he had looked absolutely spectacular in his run to the top, and many pegged him to be the future of the lightweight divison.
Now, things are not so cheery in the Diaz camp.
First, he lost to Henderson in a blowout decision.
Then, Josh Thomson sent him crashing to the canvas with a vicious head kick, sealing the first knockout loss of his career.
Where is he now?
A Nov. 30 clash with Gray Maynard will settle that.
For now, Diaz comes in at No. 10.
Pat Healy is a bad dude, but he was overmatched against the prodigal Nurmagomedov at UFC 165.
A well-rounded, massive lightweight, Healy can give most of the division serious problems inside the Octagon, as demonstrated by his third-round submission victory over Jim Miller at UFC 159.
After a failed drug test, this result was overturned to a no-contest, but viewers still saw exactly what Healy could do against a tough, established UFC veteran.
Healy is now 6-1 (1) in his last eight, and there is no shame in losing to Nurmagomedov, something that will become more clear as the Russian standout continues his climb up the lightweight ladder.
Gray Maynard's recent decline is troubling.
Long considered one of the top three lightweights in the world, Maynard is 1-2 in his last three fights, and the lone victory was a controversial (and boring) split-decision victory over Clay Guida.
In each of the two losses, Maynard was obliterated on the feet and knocked unconscious, so he will need to do something big against Nate Diaz Nov. 30 to reverse his course.
Nurmagomedov's UFC 165 victory over Pat Healy is bigger than the rankings reflect.
The young Russian controlled the fight, outstriking and outgrappling Healy en route to a clear decision victory, yet he moves nowhere in the rankings.
Put simply, the division is too stacked from here up to justify Nurmagomedov hopping any more established veterans.
Now, this is not to say that Nurmagomedov cannot beat each and every fighter in front of him—he just hasn't beaten anybody with enough top-level success to jump into the top six of the division.
How can we fix that?
Nurmagomedov's camp announced that they want a fight with Rafael dos Anjos. That's a good place to start.
Remember that fight Nurmagomedov wanted?
It makes all kinds of sense, and it needs to happen.
Dos Anjos comes in at a cushy No. 6 in the lightweight rankings, and his recent resume is nothing short of spectacular.
A five-fight winning streak over guys like Donald Cerrone, Mark Bocek, Evan Dunham and Anthony Njokuani shows that dos Anjos can trump a variety of styles, and he has shown significant evolution in his game with each bout.
Let's pair him with the rapidly ascending Nurmagomedov and see who deserves to make the leap into title contention.
Ladies and gentlemen, your newest challenger for the lightweight title, No. 5-ranked Josh Thomson.
While a championship fight for Thomson could be (and should be) considered generous matchmaking, Anthony Pettis' list of challengers is thin for a variety of reasons, a fact which you will see in the upcoming slides.
A head-kick knockout over Nate Diaz in his UFC debut put the lightweight division on notice, and now Thomson can establish himself as the greatest 155-pound fighter in the world as he takes on Pettis at UFC on Fox 9.
If you ask the right people, Gilbert Melendez should be the UFC lightweight champion.
A debatable split-decision loss against Benson Henderson at UFC on Fox 7 kept "El Nino" away from the division's top honor, but the California native showcased his worth even in defeat.
With a UFC 166 bout against Diego Sanchez on the horizon, Melendez will look to get back on track toward the title.
T.J. Grant is the best lightweight that we may never see fight for the title.
Despite riding a five-fight winning streak (with the last two coming by ferocious knockout), it remains unclear when, if ever, we will see Grant realize his dream of challenging for UFC gold.
It's time for Benson Henderson to get back to work.
After commandeering the UFC lightweight strap for 18 months, racking up three title defenses in the process, Henderson finds himself shedding tears over a flipped script following his UFC 164 loss to Anthony Pettis.
With his technical, powerful grappling and maniacal work ethic, though, Henderson should have no problem clawing his way back to the top of the 155-pound mountain in due time.
Anthony Pettis is the hottest thing in the lightweight division right now, and for good reason.
He submitted a powerful ground specialist in Benson Henderson to steal the belt, proving that his Brazilian jiu-jitsu is nothing to mess with.
Add in the fact that his diverse and powerful striking—not his ground game—is his specialty, and it is clear that Pettis deserves the UFC championship strap and the No. 1 ranking on our list.