Roosevelt Roberts kept his undefeated record (and 100 percent finish rate) in tact with an absolute mugging of Garrett Gross over the course of more than seven minutes of lightweight action.

Roberts (6-0) put on a grappling showcase against Gross (11-8), who wasn’t able to stop the offense from coming his way before he tapped out to a second-round submission in the featured bout at Dana White’s Contender Series 15, which took place took place at The Ultimate Fighter Gym in Las Vegas. The win earned him one of four contracts dished out by UFC President Dana White on the penultimate episode of Season 2, along with Ian Heinisch, Jordan Griffin and Juan Adams.

The desire to win the fight by submission was evident from the opening bell, when Roberts went right after Gross and tried to jump on a guillotine. He got top position through a big takedown and was absolutely relentless from on top. He mixed up ground-and-pound and submission attempts, putting what was arguably a 10-8 round on his opponent.

Roberts, 24, picked up right where he left off in the second round. He got Gross to the ground again, but this time the stoppage was within reach. Roberts broke Gross down with his pressure, forced him to give up the back, then locked in a rear-naked choke that forced the tap at the 2:13 mark of Round 2.

“It’s really sweet,” Roberts said in his post-fight interview with Laura Sanko. “I’ve came a long way. I came from – I can’t even really explain it right now – but I came too far and I had so many doubters, so many people gave up on me. I’ve spent my whole life trying to prove them wrong and I feel like I did it.”

Mayes stops Sipe with strikes in bloodbath

Mitchell Sipe (4-1) was handling himself well against Don’Tale Mayes (5-2) until a deep cut and lots of blood turned the tide of the heavyweight bout and allowed Mayes to score a second-round TKO.

Mayes and Sipe came out throwing hard shots in attempt to score an early finish. After a few minutes, though, the action slowed down. As both men became fatigued, they had to pick their shots more carefully to avoid walking into something serious.

That’s exactly what happened in the second frame, though. Mayes connected with a stepping elbow that opened a nasty gash around Sipe’s eye. Sipe was able to get through it standing, but once the action spilled to the ground, he had no chance.

With blood pouring intp his eyes and Mayes on top of him, Sipe attempted to squirm back to his feet. Mayes wasn’t having it, though, and he battered Sipe with ground-and-pound blows until the referee had seen enough and waved off the action at the 4:49 mark of Round 2.

“It feels wonderful,” Mayes said in his post-fight interview. “I felt good. Walking around at 270, that was slowing me down. I lost the weight, lost about 15 (pounds). I had better cardio.”

Heinisch wrecks Sumter for elbow KO

LFA champion Heinisch (11-1) delivered a highlight-reel knockout at the expense of Justin Sumter (6-2) in the opening round of their middleweight matchup.

Sumter started strong with top position gained by a takedown and poor guillotine choke attempt by Heinisch. He couldn’t do much significant with it, though, and the action turned around when Heinisch successfully scrambled into top position.

Heinisch did solid work from on top, methodically breaking down his opponent with short punches until he was ready to go for the finish. “The Hurricane” pinned Sumter’s head into the corner of the cage, postured up and landed a flurry of nasty elbows that put Sumter out cold at the 3:37 mark of Round 1.

“This feels great,” Heinisch said in his post-fight interview. “It’s Hurricane season. I came in with a mission, I accomplished it and I’m super proud and super happy. … I’m strong in every area, I don’t have holes, so I’m ready for the UFC.”

Griffin turns tables to submit Mitchell

Just when it seemed Griffin (17-5) was going to be in trouble against Maurice Mitchell (11-2), he turned the tables to win the fight with a slick choke.

Griffin and Mitchell attacked each other with high pace to begin the featherweight bout. Mitchell was getting some good offense in on the fee and nearly locked in a tight anaconda choke when Griffin shot in for a sloppy takedown.

Just when it seemed all the momentum was on Mitchell’s side, a dramatic change occurred. Griffin landed a left hand that dropped his opponent, but instead of following up with more strikes, he stepped over the back and sunk his forearm under the neck for a rear-naked choke. The hold was deep immediately, and Mitchell was forced to tap out at the 3:17 mark of Round 1.

“I’m happy,” Griffin said in his post-fight interview. “He had caught me with a cross, like a really good cross, and I felt like he didn’t catch me with anything but that cross – but when he hit me I saw two of him. I’m still seeing two. I was just like, ‘I’m going to swing for one of them,’ and I hit one.

“I’m extremely ready, I just want to tear it up. I’m ready to tear some (expletive) up. I just want to fight the hardest guys, though. I don’t want anybody taking it easy on my or, ‘Hey man, we’re going to throw you a bone.’ No. I want the hardest guys. I want to be No. 1, and I want to be the champion.”

Adams tees off on Teed for the TKO

Adams (4-0) showed that he’s not just a massive physical specimen, but he also has some impressive raw talent, earning a brutal first-round TKO beatdown of an utterly overmatched Shawn Teed (5-2).

At 6-foot-5 and with a frame that forces him to cut weight to reach the 266-pound heavyweight limit, Adams, 26, imposed his will on Teed from the opening bell. He landed a massive flurry against the fence in the opening seconds, immediately forcing his opponent into a defensive shell.

Teed somehow survived the early shots, but that just allowed Adams more opportunities to inflict damage. He landed more shots that caused Teed to pull guard. Teed attempted to roll into a heel hook, but Adams escaped and got on top, where he got into position to the finish.

Adams attempted to apply a rear-naked choke but didn’t have the right angle. He then advanced into mount and unleashed a flurry of ground strikes that caused referee Marc Smith to step in to call the fight at the 4:17 mark of Round 1.

“I’m as happy as I was when I started,” Adams said after this victory. “This was expected. It is what it is. … There’s no way that scrub was anywhere near my level. It would have been close if he had hit the gym more and laid off the barbecue, but I was so much stronger than him.”

Dana White’s Contender Series 15 results include:

• Roosevelt Roberts def. Garrett Gross via submission (rear-naked choke) – Round 2, 2:13
• Don’Tale Mayes def. Mitchell Sipe via TKO (strikes) – Round 2, 4:49
• Ian Heinisch def. Justin Sumter via knockout (elbows) – Round 1, 3:37
• Jordan Griffin def. Maurice Mitchell via submission (rear-naked choke) – Round 1, 3:57
• Juan Adams def. Shawn Teed via TKO (punches) – Round 1, 4:17

For more on Dana White’s Contender Series 15, check out the MMA Events section of the site.