In a discussion of some of the elite lightweight fighters in the world, you’re likely to recognize most of the names. There’s Anthony Pettis, Donald Cerrone, Justin Gaethje… wait, what?

Yes, that’s right, Justin Gaethje. Gaethje is the lightweight champion of the World Series of Fighting, run by “Sugar” Ray Sefo and probably the No. 3 mixed martial arts organization behind the UFC and Bellator MMA. While fighters like Pettis, Cerrone, Rafael dos Anjos and Bellator’s Will Brooks and Michael Chandler tend to grab the headlines, Gaethje has compiled a 14-0 record, grabbed the WSOF lightweight title and scored eight knockout victories in his last nine fights. The one exception was a split decision victory over former UFC lightweight Melvin Guillard on a WSOF card last year.

The fight with Guillard was originally billed as a title contest, but it was changed to a non-title affair after Guillard failed to make weight (the guy just can’t get out of his own way, can he?). That didn’t change the fact that Gaethje and Guillard engaged in a brutal slugfest of their own, with Gaethje still walking out the victor.

Gaethje’s most recent title defense came on March 28 when he notched a TKO victory over Luis Palomino. Gaethje looks to be in no danger of losing his belt anytime soon, which perhaps begs the hypothetical: Should he jump to the UFC and engage in some truly amazing fights?

The UFC has no shortage of lightweight fighters who would create excellent match-ups for Gaethje. Here are the top five picks:

1. Donald “Cowboy” Cerrone: Really, does this need any explanation? Cerrone loves to scrap and is always aiming for a knockout victory. He engaged in his own slugfest with Guillard, much like Gaethje. A good old-fashioned brawl between Cerrone and Gaethje could be one for the ages.

2. Anthony Pettis: During his victory over Palomino, Gaethje showed a few unorthodox moves we usually see from Pettis, including a cartwheel kick. Imagine if Pettis tried the Matrix kick that helped him secure a victory over Benson Henderson in World Extreme Cagefighting. Better yet, imagine if Gaethje tried that himself. A bout between Gaethje and Pettis might allow us to see moves never performed before in the Octagon.

3. Gilbert Melendez: Here’s another fighter who loves to trade punches. Melendez was part of what many consider one of the greatest UFC fights of all time, when he defeated Diego Sanchez in 2013. Melendez’s fights with Josh Thomson in Strikeforce are well known too. It’s hard to see a fight between Melendez and Gaethje going any way except for those two standing toe-to-toe in the middle of the Octagon raining punches on each other.

4. Khabib Nurmagomedov: Like Gaethje, Nurmagomedov is undefeated. He’s also considered the next big thing at lightweight and is expected to receive a title shot if he defeats Cerrone at UFC 187 in May. Nurmagomedov’s last three victories have been by unanimous decision, including one over current UFC lightweight champion Rafael dos Anjos. That probably wouldn’t do for Gaethje, who might help prove if Nurmagomedov is the real deal by forcing him to really go for the finish — because that’s exactly what Gaethje would do.

5. Rafael dos Anjos: The current UFC lightweight champion was a heavy underdog to Pettis last month, but he won the belt by completely smothering Pettis and taking away his trademark offense. Could he do the same to Gaethje? Would Gaethje’s knockout power be neutralized by Brazilian’s takedowns and jiu-jitsu? Would dos Anjos be content grinding out another decision victory? A fight with Gaethje would present a fascinating mix of styles.

It will probably be a long time before we see any of these fights, if we see them at all. Gaethje seems firmly entrenched as the WSOF’s lightweight champion, and I’m sure the organization has no plans on letting him get away. But if Gaethje ever made it to the grand stage of the UFC? Oh, the show he could put on inside the Octagon.