Conor McGregor’s rise to the top of the UFC has been explosive and unprecedented. In an organization that had historically put their physically bigger fighters on the marquee and ignored the smaller ones, the 145-pound McGregor originally seemed unlikely to make a mark, even after the UFC unveiled their new featherweight division after acquiring Elite XC and their roster of smaller, quicker fighters. But then McGregor opened his mouth.

With a strong Irish accent and the ability to weave trash talk into poetry like a modern day Muhammad Ali, McGregor took the UFC by storm. He won fight after fight, often correctly predicting the round and method, earning the nickname “Mystic Mac.” He fought (and talked) his way into some of the biggest fights in UFC history, in terms of PPV buys. He dethroned Jose Aldo at featherweight, taking just 13 seconds to knock out a man who hadn’t lost in a decade. Then he made history by knocking out Eddie Alvarez for the lightweight title, becoming the first fighter to hold two UFC belts concurrently.

The UFC may have taken away his featherweight title, but that’s not likely to stop McGregor’s momentum. It doesn’t seem like there is anyone in the UFC who can challenge him, save for that fluke loss to Nate Diaz (we say fluke because Diaz was a last minute replacement and the fight was at 170-pounds, a weight limit that was brand new to McGregor at the time). So we started thinking — which great UFC fighters of the past could have matched up against McGregor and come out with their hands raised? We’re talking about fighters at the absolute prime of their careers, since some of these names are still competing well into their middle (and late) 30s. So strap into your time machine and let’s travel back to visit these ten fighters from the past who we think could topple McGregor. For the sake of some sort of realism, we are sticking with fighters who primarily fought at welterweight or lower.

10. Diego Sanchez

For one brief exciting moment in his career, Diego “Nightmare” Sanchez looked like a man possessed. Sanchez started his professional MMA career going 17-0, which included wins that saw him crowned the Season One champion of The Ultimate Fighter reality show. He would lose two close decisions before rattling off four straight wins in 2008 and 2009 to earn a shot at B.J. Penn and the lightweight title. Marching to the octagon with his trademark “Yes!” chants, Sanchez would come up short and has never actually held a UFC title.

But let’s pretend that the Sanchez from 2009 could be brought back to face present day McGregor for the lightweight title. It would be a wild stand-up affair, which would be nothing new for Sanchez, who is the owner of seven Fight of the Night bonuses in his UFC career. Sanchez also had a remarkable chin, meaning that he could probably walk through that famous McGregor left hand to get his hands on the Irishman. It would be close, which is why Sanchez kicks off our list rather than tops it, but we think Nightmare could pull out a victory.

THE CANADIAN PRESS/Neil Davidson

9. Jake Shields

In 2008 and 2009, Jake Shields was considered the best fighter not currently under UFC contract. He won the Elite XC welterweight title in ’08 and then the Strikeforce middleweight belt in ’09, before finally making the leap into the UFC. A narrow decision win over Martin Kampmann led to a title fight against welterweight kingpin Georges St-Pierre in 2011, which Shields would ultimately lose. But there’s no shame is losing to GSP, since most fighters did.

Shields is 37 now, but back then he picked up victories over big names like Carlos Condit, Robbie Lawler, Dan Henderson, Tyron Woodley, and Damian Maia. At the height of his powers, Shields would have been a terrible matchup for the shorter, smaller McGregor.

THE CANADIAN PRESS/Chris Young

8. Jon Fitch

On one point in his career, Jon Fitch went seven years with only a single loss on his record (a title fight against Georges St-Pierre at UFC 87). From July 2003 to August 2010, he was 21-1. Even his next non-win fight, against the always tough B.J. Penn, ended in a judges draw — technically not a loss. No one would ever confuse Fitch with an exciting fighter though, as his prodding, grinding style led to a lot of boring (but technically brilliant) wrestling matches. You can’t argue with the record though, as he was fairly unbeatable for a long time, notching wins over the likes of Thiago Alves, Diego Sanchez, and Paulo Thiago. He too would have a decent size advantage over McGregor, assuming the two would fight at welterweight. We’ve seen McGregor look uncomfortable on the ground, and Fitch would certainly aim to take down the Irish star.

Via Heidi Fang/Fight Corner

7. Khabib Nurmagomedov

Here’s one matchup that’s still possible, as both men could be currently considered “in their prime.” The 28-year-old Nurmagomedov remains undefeated in his career at 24-0, including eight straight victories in the UFC. He has been angling and begging for a shot at McGregor, especially now that McGregor has jumped up in weight to claim the lightweight championship. A win over Michael Johnson at UFC 205 puts the Russian squarely in position to fight McGregor, but so far the fight hasn’t been made. McGregor apparently wants some time off while his girlfriend is pregnant (the baby is due in Spring 2017), meaning that Nurmagomedov may take another bout in the meantime (possibly against Tony Ferguson).

Nurmagomedov has said on more than one occasion that his style would be a nightmare matchup for McGregor, and accused the champ of ducking him. This is a fight the UFC should make as soon as humanly possible, so that fans don’t have to think “what if” five or ten years down the road.

THE CANADIAN PRESS/Chris Young

6. Jose Aldo

We’re not taking anything away from Jose Aldo. He was the king of the smaller weight classes for a decade. From May 2006 to December 2015, Aldo won all 18 of his fights, many in decisive fashion (half of those victories came by KO or TKO). But that all came to an end on December 15, 2015, when McGregor and Aldo finally faced off for the featherweight championship, after almost a year of promotion and anticipation. Thirteen seconds later, it was all over when McGregor landed a left that knocked Aldo out cold. The King is dead, long live the King!

Let’s imagine the fight had taken place when Aldo was still 26 or 27. When he was beating guys like Kenny Florian, Mark Hominick, Frankie Edgar, Urijah Faber, and Chad Mendes. Before a long injury layoff and (maybe) when he was still hungry to prove himself as the best. Honestly, we think Aldo would still have a great chance of beating McGregor if they fought tomorrow. Other than that one lucky (but still extremely skilled) left hand from McGregor, Aldo is still one of the most dominant fighters MMA has ever seen.

(AP Photo/John Locher)

5. Jens Pulver

We’re going waaaaaay back with this pick. Jens “Little Evil” Pulver is considered by many to be the founder of the UFC lightweight division, being the very first person in the promotion to be named the champion when he defeated Caol Uno at UFC 30. He also holds victories over the likes of Dennis Hallman and B.J. Penn in those early days of the UFC, when it was still banned in many jurisdictions. While his final career record of 27-19-1 doesn’t look that great on paper (because it’s not), Pulver carried on fighting until almost his 40th birthday, picking up bunch of losses in the final third of his time in the cage.

While we have no way of knowing how Pulver, a gritty UFC pionner, would fare against the McGregor, the epitome of a modern MMA fighter, we think Pulver has more than a fair chance. He won his early fights by TKO, submission, decision, and knock out, proving he was a well-rounded fighter. He also went 4-0 as a professional boxer, which may help him avoid that famed McGregor power left in this fictional fight.

Via FOXSports.com

4. Matt Hughes

Before Georges St-Pierre took his crown and ruled over the welterweight division, Matt Hughes was the man. He won the UFC welterweight championship by slamming Carlos Newton into oblivion, in a clip that has been replayed millions of times since. After five successful title defenses, he was eventually submitted by B.J. Penn at UFC 46. No matter though, because he regained the now-vacant belt later that same year at UFC 50 by submitting Georges St-Pierre (a rare feat). Two more title defenses would follow before Hughes finally passed the torch to St-Pierre for good.

Hughes, at his best, was a hard puncher and a terrific wrestler (he wrestled all through high school and college, becoming a two-time All-American). Basically a good ol’ country boy from Hillsboro, Illinois, Hughes was also one of the toughest competitors to ever step into the octagon. There’s a good chance he could walk right through McGregor’s punches and ground and pound the smaller fighter into the mat.

(AP Photo/Jae C. Hong, File)

3. Royce Gracie

Yep, we went there. The godfather of it all, Royce Gracie, made a name for himself by beating fighters who, on appearance alone, should have clobbered the Brazilian legend. Fun history lesson: the very first UFC was less about seeing who won, and more about showcasing and advertising a previously little-known style of fighting: Gracie Jiu-Jitsu. UFC 1 was an eight-man tournament that saw Royce, all 170-pounds of him, face off against bigger, stronger fighters and come out on top thanks to a revolutionary (at the time) style of fighting that saw him submit three opponents in a single night. In fact, he only needed less than five minutes of total fight time to claim those three wins.

Could Gracie beat McGregor? The two eras are so different, it’s impossible to say for sure. But McGregor is weak when it comes to submission defense and Royce Gracie (and his family) literally invented the submission game, so yeah, Gracie could probably find a way to make McGregor tap.

Via wbbjj.com

2. B.J. Penn

We struggle with how to accurately remember the career of B.J. Penn. He was one of the most naturally talented fighters in UFC history, but could sometimes be one of the laziest. He would often slack off during training, assuming his natural skill would be enough on fight night. And often, he was right. But when Penn was really motivated, he looked unbeatable. He was the second fighters in UFC history to win championships in two different weight classes (Randy Couture did it first), as he claimed both the lightweight and welterweight championships at different points in his career.

Penn fought the best of the best, including many on this list: Matt Serra, Caol Uno, GSP, Matt Hughes, Renzo Gracie, Jens Pulver, Diego Sanchez, and Frankie Edgar. He’s still going, at age 37, but a fight between Penn and McGregor with the Penn from 12-15 years ago would probably (theoretically) smash every MMA PPV record that exists. And Penn is so crafty and well-rounded, he could probably take home the win.

THE CANADIAN PRESS/Neil Davidson

1. Georges St-Pierre

When former UFC welterweight champion Georges St-Pierre was at the top of his game, he was virtually unbeatable. Only Anderson Silva was a more dominate champion in a single weight class (and he’s not on this list because he fought at 185-pounds or higher). GSP made skilled strikers look silly by wrestling them to the ground and grinding out victories. St-Pierre lost only twice in a decade of UFC fights, and finished his UFC run with 11 straight wins with the belt on the line.

McGregor had his ground game weakness exposed against Nate Diaz, and a potential McGregor-GSP matchup would surely follow that same pattern. It’s also worth pointing out that while McGregor has fought twice at welterweight so far, St-Pierre was regarded as one of the biggest welterweights ever, seemingly having figured out the exact science behind a large weight cut. GSP often stepped into the cage weighing 190-pounds or more, even though he weighed in at 170-pounds just 24-hours earlier. McGregor would give up a lot of size in this bout and probably end up the same as almost every other GSP opponent — defeated.

THE CANADIAN PRESS/Ryan Remiorz