The finish came at the 1:14 mark when Jackson tapped. It was the first time Jackson was finished early inside the Octagon.
"I'm in the best shape of my life," said Jackson, after falling to 32-9. "I expected to come out here and close the distance and overthrow Jon Jones. I thought it was hype, but the kid is good.
"The kid is here to stay. Whoever is fighting him next, I don't see [anybody] beating him. This was the best Rampage and he had me mesmerized."
Rashad Evans will get the next shot at Jones, though no date has been set for that fight.
Jones was in control of the fight from the very beginning. He used his superior reach advantage to land kicks and jabs that prevented Jackson from mounting any type of offense.
In the third round, Jones took the fight to the ground and landed a left elbow that opened a cut over Jackson's right eye.
The youngest UFC champion ever and youngest to compete in a title bout was confident the end was near for Jackson entering the fourth round.
"My coaches told me that going into the fourth round that he was breaking a little bit and if I was going to do it this was the time," Jones said.
"The game plan was to prove that we could strike with Quinton Jackson. He insulted my striking game before the fight."
Hughes not retiring after KO loss
The punch dropped Hughes, and Koscheck (16-5) began pounding. Hughes was knocked out at 4:59 of the first round.
"He's a legend and I'm proud to get to fight Matt Hughes," Koscheck said. "It was nice being on the shelf.
"I'm growing as a person and a fighter."
Hughes (45-9) is 37 years old and there had been talk that this fight might be his last. But Hughes put an end to such talk.
"I'm not retiring," Hughes said. "I'm going to tell UFC to put me on the shelf. We'll see after that."
Hughes looked good early in the fight during standup action. He connected regularly with a right jab that had Koscheck backing away.
Hunt outlasts Rothwell
The judges scored it 29-28, 29-27, 30-27 for Hunt. ESPN.com had it 29-28 for Hunt.
Despite suffering a cut over his right eye in the first round, Rothwell was able to get Hunt (7-7) to the ground and score with hard punches.
But the momentum turned in Hunt's favor during the second round. Hunt was able to avoid being taken to the ground on several occasions. He also pushed the action that forced Rothwell to burn energy in the high altitude.
Rothwell, who returned to action for the first time in 15 months from a torn ACL, was exhausted in the third round and could barely hold up his hands.
Hunt was beginning to tire also, but he had enough energy to get Rothwell (31-8) on his back, batter him and secure the win.
Tired Browne beats Broughton
Travis Browne stopped each of his previous five opponents in the first round, but that streak ended against Rob Broughton. Browne was forced to go the distance, and he came away with a unanimous decision.
All three judges scored the fight 30-27 for Browne, as did ESPN.com.
"People thought this [fight] was a step down from Stefen Struve," Browne said. "But he was tough, he took my best. I will come back stronger."
Browne improved to 12-0-1.
After two rounds, Browne was breathing heavily. He took Broughton to the ground in the third round to secure the win.
Broughton demonstrated no takedown defense in the fight. He fell to 15-6-1.
Diaz outboxes, submits Gomi
"I'm happy to get the win," Diaz said. "[Gomi's] dangerous. But I knew [his body wasn't yet sweaty and] slippery, so he wasn't going to get out of my triangle."
It was Diaz's first fight at lightweight since dropping back-to-back bouts at welterweight. The move back to 155 pounds had no negative impact on Diaz, who looked physically strong and started the fight aggressively.
He landed straight right jabs and followed them beautifully with hard lefts. Diaz dropped Gomi several times in the round with left hands.
But it was Diaz's performance on the ground that would finish Gomi (32-7, with one no contest). Diaz got Gomi in a vulnerable position, worked a few transitions, secured Gomi's left arm and forced him to tap.
Ferguson breaks Riley's jaw
Lightweight Tony Ferguson landed a left uppercut that broke the jaw of Aaron Riley in the middle of the first round. Riley was unable to come out for the second round, giving Ferguson the victory by TKO.
"It was hard to close the gap on this veteran," said Ferguson, "The Ultimate Fighter" Season 11 winner who improved to 12-2. "We worked really hard on fighting a southpaw."
After suffering the injury, blood began streaming from the mouth of Riley (30-13-1). Though Simpson continued to fight, he was visibly struggling to mount any type of offense.
He made it through the round but was in no condition to continue.
Boetsch wears down Ring
The judges scored the bout 29-28, 29-28 and 30-27. ESPN.com scored the fight 29-28 for Boetsch.
After spending the first two rounds standing, Boetsch was able to take Ring down often in the third and batter him.
Boetsch, a former light heavyweight, improved to 2-0 at 185 pounds. He is 14-4 overall. Ring suffered his first pro loss, dropping to 12-1.
Successful Octagon return for Assuncao
Junior Assuncao registered an uneventful unanimous decision over UFC newcomer Eddie Yagin in a featherweight bout.
The judges scored the fight 30-26, 30-26 and 30-27. ESPN.com had it 30-27 for Assuncao. It was Assuncao's first appearance inside the Octagon since September 2007.
Assuncao (13-4) approached the hard-hitting Yagin (15-5-1) cautiously in the standup but was able to get the fight to the ground in each round. In the third, Assuncao took Yagin down and landed left hands repeatedly to secure the win.
Mizugaki overpowers Escovedo
A Takeya Mizugaki left hook finished Cole Escovedo at 4:30 of the second round in his bantamweight fight. Mizugaki (15-6-2) was the more aggressive fighter throughout, landing numerous right-left combinations to the body and head.
Escovedo dropped to 17-8 and has lost each of his two fights in UFC.
Te Huna finishes Romero in first
Romero when down and Te Huna landed several more punches that forced referee Tim Mills to wave the bout off at the 47-second mark.
Te Huna improved to 13-5; Romero (11-3) dropped his second fight in a row.
Franklin McNeil covers mixed martial arts and boxing for ESPN.com. Follow him on Twitter at www.twitter.com/Franklin_McNeil.