Jon Jones defended his light heavyweight championship once again via a split decision against Thiago Santos in the main event of UFC 239 from Las Vegas on Saturday.

Jones was able to do just enough to keep Santos at bay. The challenger, who suffered an apparent leg injury early in the bout, brought the fight to the champion in a valiant effort.

Both fighters gave a measured effort in the first round. Santos attacked patiently with leg kicks and put together some moments including a punch that took out Jones' mouthpiece, but he mostly won the round based on his work on Jones' foundation:

The would slow up a bit in the second round as Santos appeared to tweak his knees after a botched kick. Jones took advantage with a little more aggression and even caught him backing up to knock him off balance:

The knee continued to be an issue as Santos struggled with movement and power. The champion also began to open up landing big elbows and putting Santos on the defensive. 

That trend continued in the fourth as Santos' output waned. Jones slowly ramped up the pressure and took advantage of an immobilized Marreta to take another round heading into the fifth. 

The injury set up a strange final round as Santos gritted it out with limited movement, yet Jones never opened up enough to take advantage. Marreta made it through the round and even landed a few flurries to make it a difficult round to judge:

The result was a difficult fight to score and a perplexing performance from Jones. 

Bones' latest title defense adds another accomplishment in what has been a busy stretch for the champion. After fighting just three times from January 2015 to July 2017, he's making up for lost time with three wins in a little over six months, including a win over rival Alexander Gustafsson and Anthony Smith.

The champion's domination of the light heavyweight division has been thorough when he's active in the cage. He now holds wins over four of the five fighters who occupy the top five of the rankings, and it's difficult to even find an intriguing matchup for him at 205 pounds.

But don't expect that to force his hand in a move to heavyweight. He seems content to stay right where he is for now.

"I am thinking of heavyweight. But it's not in the forefront," the career 205-pounder said on Ariel Helwani's MMA Show in June. "I'm making weight just fine. People are assuming I'm a lot bigger than I am. I'm a full-sized light heavyweight. Grown-man strength. I feel like I'm getting stronger. Heavyweight will come. But things are going so well where I'm at, there's no reason to change anything."

After a close bout with Santos, there's a little more intrigue to Jones staying at light heavyweight for now. A rematch against a healthy Marreta sounds appealing and his success might open the path for other opponents to have a gameplan that could work against the longtime king. 

Santos may have opened up a once seemingly closed division with his performance even with Jones cementing his spot as the top light heavyweight.