Former UFC lightweight champion Benson Henderson is no stranger to controversy and for the third time in five fights he found a way to eke out a split decision victory, this time besting Josh Thomson in Chicago on Saturday night.

Henderson (20-3) was fighting for the first time since losing his belt to Anthony Pettis back in August, with his mission starting now to reclaim the top spot that he held for the better part of 18 months. Thomson was hoping to earn a title shot of his own with a win, but the final judges' call put him back in line with a number of other contenders.

One thing that can't be disputed: the fight, round by round, was closer and closer with neither fighter dominating the other.

The first round between Henderson and Thomson turned into a great grappling affair full of submission attempts, takedowns and scrambles. The former Strikeforce champion took control early with a slick move to put Henderson down, where he immediately took his back and locked on a body triangle.

Thomson (20-6, 1 NC) tried to get a choke in, but Henderson battled back and got the fight on the feet where he reversed course and almost pulled off a standing head and arm choke. Henderson transitioned from there to pulling guard with the move, but Thomson survived the round.

Henderson powered back in the second round using the clinch to push Thomson against the cage and controlling the pace of the fight for the biggest chunk of the five-minute session. Thomson once again got Henderson's back during the round, but failed to execute any serious submission attempts.  Still, it was a dominant position to take during the round, which could have easily played into the judges' scorecards.

Between rounds, however, Thomson was heard telling his corner that he may have broken his thumb, and that would play a major factor in the remaining time left in the fight.

The third round saw more offensive output from Henderson, as Thomson seemed to fade into the background during each exchange and grappling attack. While Henderson didn't do any serious damage during the round, all Thomson could do was play defense. The fourth saw a strong comeback from Thomson as he relied heavily on his wrestling and grappling to put Henderson down when the round started and once again taking his back at the end.

With Thomson riding Henderson's back, the San Jose fighter put his arm in the air and motioned the Chicago crowd to applaud the action in the cage.

As the fifth and final round began, both Henderson and Thomson looked to score those crucial points that could mean the difference between the thrill of victory and the agony of defeat. Thomson popped Henderson with a good right hook midway through the round while the former UFC champion came back with a knee to the body and a thunderous leg kick to his opponent's thigh.

As the fight came to an end and each round closer than the next, the judges' scorecards were likely to be all over the place and sure enough a split decision was rendered that left the Chicago crowd a bit shocked by the final call.

The scores ended 48-47 Henderson, 48-47 Thomson and 49-46 for Henderson -- giving the former UFC champion the victory. It marked Henderson's third split decision win in his last five fights.

As Thomson left the cage and walked by the crowd, he was shaking his head while saying 'no' over and over again, obviously despondent from the scores handed back by the judges from Illinois. For his part, Henderson immediately shoved his signature toothpick in his mouth and didn't seem rattled in the least that the crowd appeared to land on his opponent's side for the decision.

The final numbers did seem to give Henderson the edge, however, as he more than doubled Thomson's striking output while equaling him in takedowns for the fight. The statistics don't always tell the story though and Thomson did not look happy at all that he didn't come away with the win.

A Henderson win now shakes up the lightweight division, which could land former Strikeforce champion Gilbert Melendez in the cat bird's seat with a title shot against Anthony Pettis wide open now that Thomson is out of the picture. The UFC's final decision won't be made until Pettis recovers from knee surgery, but right now there is no clear cut No. 1 contender, so it will be interesting to see what UFC president Dana White and matchmaker Joe Silva opt to do next.