Couture turns back time, stops Coleman

Reason to smile: Randy Couture breathed new life into his career by stopping Mark Coleman. Ric Fogel for ESPN.com

LAS VEGAS -- It was never in doubt.

In a battle between beloved hall of famers, Randy Couture reigned supreme, as he submitted Mark Coleman with a second-round rear-naked choke in the UFC 109 "Relentless" headliner on Saturday at the Mandalay Bay Events Center.

Drifting briefly into a state of unconsciousness, Coleman went out on his sword 69 seconds into Round 2.

The incomparable Couture set the tone with his boxing but deftly moved to the clinch midway through the opening round, pressed Coleman against the cage and went to work with his patented dirty boxing. A dejected Coleman, 45, retreated to his corner after a lopsided period. He had no answers and seemed to know it. Reality bit.

Couture rocked Coleman with a left hook in tight in the third round, pushed again into the clinch and took down the former Olympian with surprising ease. From there, the two-division champion flurried on "The Godfather of Ground-and-Pound," seized back control and cinched the choke for the victory, his second in a row since his return to the light heavyweight division.

"I'm having a blast," said the 46-year-old Couture. "I feel like I'm improving each and every time I get out here. This is my third fight in seven months, and it feels good to be so active."

Coleman is 1-2 in the UFC since returning after a decade-long departure.

"Wow, the guy's tough," he said of Couture. "The guy's real tough. I don't know what the hell happened. I'm disappointed. I think I can do better. I won't quit. I'll be back."

Sonnen upsets Marquardt

In a near-virtuoso performance certain to solidify his place as one of the world's premier middleweights, Chael Sonnen defeated former King of Pancrase Nate Marquardt by unanimous decision in the co-main event. All three judges scored the bout 30-27 in the Team Quest veteran's favor.

Marquardt twice threatened with guillotine chokes. He also cut the outspoken Oregonian with an elbow from the bottom.

"He hurt me early on, even when I was on top," Sonnen said. "I was hurt from the first round. I just had to hang in there."

Sonnen was relentless in neutralizing his foe's considerable offensive firepower with overwhelming top control and stout ground and pound. An underdog yet again, Sonnen seized command from the start and never let up. Leaning heavily on his amateur wrestling background, he grounded Marquardt at will and left the 30-year-old Brazilian jiu-jitsu black belt few openings on which to exploit. His takedowns were many.

Marquardt, in a last-ditch effort to prevent defeat, cinched a tight guillotine choke in the third round, but fatigue got the best of him and allowed Sonnen to escape. Marquardt reversed position late and fired away with some of his own ground-and-pound, though his efforts went for naught.

"I'm here to be the king of the mountain or I'll move on in life and do something else," Sonnen said. "I think I can beat any man God ever made."

In defeat, Marquardt fell to 29-9-2 overall.

"I think I just executed my game plan the wrong way," Marquardt said. "I really don't think I should have lost that fight. I felt good. I think I kind of let him take control with the takedowns, and that was the key."

Thiago submits Swick

Paulo Thiago took out another American Kickboxing Academy welterweight, as he choked Mike Swick unconscious with an airtight D'Arce 1 minute, 54 seconds into the second round.

Swick, who has lost consecutive fights for the first time as a professional, had never before been submitted.

Thiago threw and landed the more meaningful strikes in Round 1, as the two world-ranked welterweights waded through an extended feeling-out process. In the second round, Swick sent Thiago backpedaling toward the cage with an overhand right but walked into a counter left hook that put him on his backside. Thiago swarmed, locked up the choke and waited for Swick to fade to black.

Maia outpoints Miller

Decorated Brazilian jiu-jitsu black belt Demian Maia outperformed former International Fight League middleweight champion Dan Miller en route to a pedestrian unanimous decision. Scores were 30-27, 29-28 and 29-28 for Maia, whose win helps him climb back into title contention at 185 pounds.

The once-beaten Maia held his own standing and grounded Miller with takedowns in the first and third rounds. Miller stung the Brazilian with a right hand in the final stanza but left himself vulnerable for the takedown, and Maia capitalized. From there, he neutralized the AMA Fight Club standout with an effective mixture of strikes and suffocating top control against the cage, winning for the 12th time in 13 fights.

"I'm sorry I couldn't finish the fight," said Maia, who went the distance for the first time in seven UFC appearances. "I always try to finish the fight."

Serra flattens Trigg

Former UFC welterweight champion Matt Serra notched his first win in nearly three years, stopping Frank Trigg on first-round strikes in a one-sided encounter at 170 pounds. The finish came 2 minutes, 23 seconds into Round 1.

Serra, 35, worked effectively to the legs and body early in the match, then floored Trigg with a booming overhand right as the two exchanged in the center of the cage. He followed with three powerful punches from the top that necessitated intervention from the referee. Serra put an exclamation point on the win with his trademark one-handed cartwheel, as a dazed Trigg, his UFC career perhaps at an end, lay nearby.

"Thank God for that overhand right," Serra said. "I just had to wing that thing. I believe in my stand-up. It's not pretty, but [when] I land it, it hurts."

Brian Knapp is a contributor to Sherdog.com.