One door closes and another one opens. Whether Randy Couture fights again remains to be seen. Less uncertain is the fact that Couture’s reign over the UFC heavyweight division is over. At age 45, he probably has enough left physically to continue to fight as a special attraction. However, as long as Brock Lesnar is an active fighter for the UFC, Couture will never wear UFC heavyweight gold again.

And so the Brock Lesnar era begins. From day one I’ve been intrigued by the prospect of Lesnar crossing over into MMA. Several years ago I participated in a seminar conducted by Pat Miletich in Cherry Hill, N.J. During a question and answer session the proceeded the seminar, I asked Miletich to share his thoughts on Lesnar having been aware that the 2000 NCAA champ had spent time at Miletich Fighting Systems while he evaluating whether he was going to pursue MMA.

In hindsight, my phrasing of the question was ill-advised. “Does Brock Lesnar have any chance to be successful in MMA?” The nature of the question prompted the normally congenial Miletich to shoot me a look of bewilderment, as if to say, “Are you f—– kidding me?”

In my defense, Lesnar was still essentially a professional wrestler, as his first round prison-style beating ofMin Soo Kim during FEG’s “Dynamite USA!!” show still hadn’t taken place. However, Miletich had seen all he needed to see during Lesnar’s stay at Champions Gym in Davenport, Iowa.

“He’s a 265 pound Matt Hughes,” quipped Miletich.

The statement was made while Hughes was reigning supreme as the consensus number one welterweight in the world. That response from a trainer of champions was all I needed to hear to know that Lesnar was going to be a force to be reckoned with.

Last night’s second round TKO victory over Couture has left those critical of Lesnar’s pro wrestling credentials with no ammunition left to fire with. The undeniable truth is that Lesnar is not only a one-of-a-kind athlete the likes MMA has never seen, but he will retain the undisputed UFC heavyweight title for as long as he wants after unifying it against the winner of December’s Antonio Rodrigo Nogueira vs. Frank Mir bout.

Some might say the above prose is a little presumptuous considering that Lesnar has all of four fights to his credit. But if his inexperience wasn’t a factor last night against a tactical wizard such as Couture, when will it ever be? In the end, Lesnar’s lack of experience was not a factor even in spite of Couture’s attempt to try and exploit it. The five-time UFC world champion body-locked Lesnar and pressed him against the cage on multiple occasions. When the fight hit the floor, Couture had Lesnar on his back but was unable to inflict any serious damage and was not successful in controlling the wrestling position for an extended period of time.

If Lesnar made any mistakes last night, I didn’t see them. And apparently Couture didn’t see any either, as Lesnar gave him few openings in which to work with. Lesnar is by no means perfect, but his off-the-charts athleticism is enough to compensate for any shortcomings he might have. To steal a pro wrestling catch-phrase, the man is just a genetic freak.

The most staggering number in my mind was the advantage that Lesnar had when it came to the “measurables.” Despite standing just one in taller than Couture, Lesnar still held a six inch reach advantage at 81” compared to Couture’s measured reach of 75″. Couture may have summed up the reason for the loss best during his post-fight interview with Joe Rogan when he pronounced, “He’s just a big son of a bitch. And it’s as simple as that.” Reasons for losing are rarely ever so quick and easy, but considering Couture’s tremendous technical prowess, it probably is just that simple.

The other issue was the disparity in weight. Lesnar outweighed Couture by at least 55 pounds last night — at least. In the future, Lesnar is unlikely to have such a weight advantage again because no sane man will ever enter the cage against him and give up that much weight. Seeing the sheer girth of Lesnar was a sight to behold (and no, that’s not a phallic reference to the tattoo on his chest); the man is just wide. It seemed like you could stand two normal human beings back-to-back and Lesnar would still be thicker. Seeing Couture standing next to Lesnar during the pre-fight staredown, I thought Randy had cut to middleweight.

From here on out, the opponents will be bigger and stronger but Lesnar will always have the advantage in weight. Much like the NBA in which the center position is now dominated by what we used to call power forwards, the days of super-heavyweights shrinking themselves down to heavyweight in MMA are over.

As we sit here today, there’s only one man in the world capable of beating Lesnar and politics will ensure that a Lesnar vs. Fedor Emelianenko matchup never takes place. In the minds of the mainstream fan, nothing exists outside of the UFC universe. For all intent and purposes, it’s Brock Lesnar’s world now and other heavyweights just walk in it. As long as Lesnar continues to push himself during training and avoids the temptation to dialing his training routine back, nobody currently on the UFC roster will be able to touch him. Not Nogueira, not Mir, not Cain Velasquez, not Shane Carwin, and not Gabriel Gonzaga, etc.

As a self-confessed PRIDE mark, even I have to acknowledge that Lesnar is a bad matchup for Nogueira. Nogueira is an amazing human being and an incredible fighter. But his Dusty Rhodes style of fighting isn’t going to lend itself well to Lesnar’s punishing ways. If Nogueira catches a beating from Lesnar, he will not be able to mount a comeback.

And yes, I realize Mir holds a win over Lesnar. But if those two fought today, how many people would honestly pick Mir to repeat? Sorry, but I don’t see Lesnar falling for a kneebar anytime soon and prior to Mir’s hail mary submission, I couldn’t tell the difference between him and Kim.

Velasquez and Carwin are superstars in the making. They are tremendous wrestlers and super athletes. But as good as Velasquez is, I don’t see him out-wrestling a 2000 NCAA heavyweight champion and as gifted as Carwin is, I don’t see him running a 4.75 in the 40.

After last night, a Gonzaga vs. Lesnar matchup appears inevitable at some point in 2009. The former heavyweight title challenger brought his A-game last night against former two-time All-American Josh Hendricks but let’s not forget he was broken by both Couture and Fabricio Werdum. I see Lesnar doing the same.

UFC heavyweight champion Brock Lesnar? Get used to the term, as the Brock Lesnar era is upon us.