What started off as a normal Sunday afternoon at Fatburger on the Las Vegas strip turned into a battle of testosterone between undefeated boxing champ Floyd Mayweather Jr. and Atlanta rapper T.I.

So why was Mayweather swinging and punching at a place other than the boxing ring?

Well apparently, things got heated between the two celebs because of an Instagram pic that T.I.'s wife, Tameka "Tiny " Harris posted on her Instagram account, The NY Daily News reported.

In the photo, posted on Sunday, we see Tiny and Floyd Mayweather Jr.'s daughter posing together. Underneath the photo of the two ladies reads the caption "Had to come celebrate with my boo @moneyyaya Happy Birthday Bae."

Though the photo looks innocent, T.I. probably felt differently. For a few months now, rumors have surfaced that the seemingly "perfect" marriage between T.I. and Tiny has been on the rocks and headed to divorce because of infidelity.

Perhaps in T.I.'s eyes, Tiny celebrating with Mayweather's daughter meant she could have been spending time with Mayweather as well.

But again, this is all speculation.

What is apparently known is that T.I. initiated the fight. TMZ reported that Floyd was eating at Fatbuger when suddenly T.I. walked up, started yelling at Floyd, and swung at him.

As things got heated, their bodyguards broke the two men up, but that did not stop them from throwing chairs in attempt to cause some serious damage.

Though both men seemed to have left Fatburger with no injuries, a Fatburger employee was reportedly slashed during the fight.

TMZ obtained two videos of the fight that both contain explicit language. At one point, we even hear Mayweather saying to T.I., "Control your B----."

Check out the videos below.

So far, there's been no comment from the reps of T.I. and Mayweather regarding the incident.

What are you thoughts on what could have caused the eruption at Fatburger? Share your comments below.