Despite it coming just weeks after blood brother Bernard Hopkins proved that a 45-year-old combat athlete doesn’t have to turn into primordial paste in the ring, returning UFC champion Randy Couture -- as much an MMA institution as the cage itself -- failed in his attempt to write yet another storybook epilogue to a peerless career.

A dark day for Couture and his fans, indeed -- mostly because opponent Brock Lesnar has lats wide enough to eclipse the house lights.

Despite looking admirably resolute in the first round and accelerated in the second, Couture was unable to surmount the massive bulk differential. (He was an alarmingly light 220 pounds to Lesnar’s 280, which isn’t far off from the size of a Western lowland gorilla.) One of Lesnar’s canned-ham fists, comically wrapped in a few piddling ounces of leather padding, grazed “The Natural” upside the head and disoriented him long enough for the former WWE acrobat to beat out a drum solo on his head.

If a big UFC fight is akin to Christmas, this was like getting socks.

It’s not that Lesnar should be maligned: Fans should probably be lucky that someone of his athletic ability is choosing to exploit it in this sport. It’s that Couture was essentially a light heavyweight fighting a super heavyweight; Lesnar’s TKO came via genetics, not ability. (His stand-up was rocky, and Couture was able to escape from smothering positions -- the problem, as Couture more or less stated, is that even a bowling ball hitting you in passing is enough to put you down.)

Tradition dictates that we don’t whine about the gulf of muscle mass between Couture and Lesnar, that heavyweights are expected to take on all comers without complaint. And usually, it works out in the lighter man’s favor. Most big men can’t afford enough oxygen to fuel their fitness-model mass and aren’t as technically proficient as their smaller counterparts.

But that’s far from the case with Lesnar, who presents all of the big boy problems (hard to move, hard to control, can’t eat too many of their punches) with few of their faults.

We don’t expect a 160-pound Kenny Florian to fight a 220-pound Rashad Evans, but Couture gets to play with a guy who looks like a CGI creation. Strange world.

That physical dichotomy might compel Couture and his fans to rally for another run in the light heavyweight division, and that would be unfortunate. At 45, Couture still has a workable level of agility against the plodding heavyweights; against sped-up athletes like Evans, Quinton Jackson or Wanderlei Silva, he’s not going to see it coming.

Couture looked solid at 228 pounds against both Tim Sylvia and Gabriel Gonzaga in 2007. Presuming he’s not fed Lesnar again, he still has opportunities on that platform. He matches up well with both Frank Mir and Antonio Rodrigo Nogueira, both men who certainly have the ability to snatch Lesnar’s title away in the spring. He’s their equal in striking, and far superior in wrestling.

Couture really doesn’t need to “earn” anything -- especially considering the flimsy UFC heavyweight division -- but if he chooses to stay busy until the belt is sorted out, there are precious few options for him. A match with Shane Carwin or Cain Velasquez is both dangerous and a low-wattage ticket mover; he’s better off taking a one-off against someone like Mark Coleman in a throwback fight before scoring another inevitable title shot.

Maybe it’s the nostalgia talking, but Couture has been here before. (He is, after all, 16-9 in his career.) Being a five-time champion means you dropped the belt five times, too.

Will he go for six? Naturally.

Etc.

With Anderson Silva having used everyone from Dan Henderson to Rich Franklin to wipe down the Octagon canvas with, Demian Maia can’t be more than one big fight away from a title bid. It’d be a brilliant matchup: Even though Silva’s jiu-jitsu is underrated, it’s not comparable to what Maia has pulled off so far … How many times will we have to see Jorge Gurgel sacrifice brain cells in a bid to become the stand-up fighter he’s not? 3-4 in the cage, there’s no longer any suspense over his career trajectory. With fighters like KJ Noons, Eddie Alvarez and others coming up for bids, how can the UFC justify Gurgel’s continued employment? ... It had to be a bittersweet night for Kenny Florian: earn another title shot and then proceed to sit tight for 8-10 months until B.J. Penn finishes his business at 170 pounds with Georges St. Pierre. I can appreciate Penn’s resolve in trying to make history as the first multiclass UFC champ, but the promotion should quit setting arbitrary guidelines for title defenses. If you’re unable or unwilling to risk the strap within six months, you should be FedExing it back to headquarters.

For comments, e-mail jrossen@sherdog.com