Maybe the questions about just how good Jon Jones is will finally come to an end.
The UFC light heavyweight faced the most difficult test of his young MMA career and passed with flying colors.
Jones finished former 205-pound titleholder Lyoto Machida with a standing guillotine at 4:26 of the second round Saturday night at Air Canada Centre in Toronto.
While Jones dominated the second round, Machida gave him much to think about in the first. Machida landed a number of hard punches that caught Jones on the chin.
It was the first time an opponent had connected flush on Jones' chin. There had been questions about the stability of Jones' jaw, but he was never in danger of being KO'd by Machida.
"He didn't have me hurt," said Jones, who improved to 15-1 by successfully defending his belt for the second time. "He's smart. He kicks very hard. He was a very tough puzzle."
The fight was nearly stopped a few minutes before Jones' submission.
Jones had taken Machida (17-3) to the ground and began landing hard strikes. A right elbow opened a huge cut above Machida's left eyebrow.
The cageside physician examined the wound and allowed the fight to continue. But with blood flowing down his face, Machida had lost any momentum he'd generated previously.
Jones would land a left hook to drop Machida. Shortly thereafter, when the fighters were on their feet, Jones applied a guillotine.
When Jones was instructed to release his hold, Machida slumped to the canvas.
Mir breaks Noigueira's arm in win
There are no more excuses for Antonio Rodrigo Nogueira.
Frank Mir stopped Nogueira via TKO by strikes during their first meeting in December 2008. He stopped him in more exciting fashion during their second showdown.
Mir improved to 15-5 after breaking Nogueira's right arm at 3:38 of the first round Saturday.
Following their first fight, Nogueira said he was less than 100 percent physically. He had no such excuse in the rematch.
Nogueira came out strong Saturday, rocking Mir with a right hand. But once on the ground, they maneuvered for position.
Mir got the advantage, locked up Nogueira's right arm and forced him to tap.
"I'm the first person to knock him out and the first to submit him," Mir said.
Ortiz seeks one more fight after TKO loss
Tito Ortiz has been talking about retirement recently; he might increase the volume of that talk after suffering a first-round TKO loss to Antonio Rogerio Nogueira.
Ortiz, the former light heavyweight champion, started strong. He landed a hard right hand that stunned Nogueira momentarily.
But Nogueira rebounded quickly and caught Ortiz with a hard left hand. Ortiz began covering up.
The fight soon went to the ground, where Nogueira (20-5) opened up with punches and elbows. A hard strike to the ribs caused Ortiz to wince in pain.
With Ortiz (16-10-1) no longer able to defend himself, the referee jumped in to stop the assault at the 3:15 mark.
"He caught me clean, the same place where I got caught by Rashad [Evans]," Ortiz said. "That body shot really hurt me.
"I'm going to take a little time off. I have one more fight on my contract. I want to get one more W, and that'll be it for me."
Ebersole holds on to earn split decision
Brian Ebersole refused to be submitted by fellow welterweight Claude Patrick.
He survived three submission attempts by Patrick in the third round to earn a split decision victory.
Two judges scored the fight for Ebersole 29-28, as did ESPN.com. The final judges saw it for Patrick 29-28.
Even before the scores were revealed, Ebersole (49-14-1, 1 no contest) expressed disappointment in his performance.
"I was upset because I wasn't able to do a lot of the things I'd hope to do," Ebersole said. "The takedowns were hard to come by, and he had good defense on the ground."
Patrick has his 13-fight win streak snapped and fell to 14-2.
Jung blasts out Hominick in record-tying style
Mark Hominick threw one punch, and missed. Then it was Chan Sung Jung's turn to get busy, and he did so immediately.
Jung needed just 7 seconds to finish Hominick in their featherweight showdown. A hard right hand caught Hominick flush on the jaw and dropped him.
From that point, Jung delivered several punches while Hominick was on his back unable to defend himself.
The 7-second knockout ties the fastest in UFC history.
"I'm always expecting to have a great win," said Jung, who improved to 12-3. "This feels great. I think I am one of the best strikers in the world."
Hominick, who was hoping to rebound from his loss in April to UFC featherweight champion Jose Aldo, now has lost two in a row. He is 20-10 overall.
"I came out a little too wild," Hominick said. "I'm disappointed. I got a little too hyped up."
Pokrajac knocks out Soszynski in 35 seconds
Krzysztof Soszynski went into his light heavyweight fight with Igor Pokrajac proclaiming he was the physically bigger and stronger man. But none of Soszynski's physical advantages mattered to Pokrajac.
The hard-punching Pokrajac landed a left hook that staggered Soszynski. He then delivered right hands repeatedly, with a few lefts tossed in, that sent Soszynski to the canvas and out 23 seconds into the opening round.
The win was Pokrajac's second in a row. He improved to 24-8. Soszynski had his two-fight win streak snapped and fell to 26-12-1.
Heavy-handed Philippou knocks out Hamman
Middleweight Constantinos Philippou has an amateur boxing background, and that experience was on full display against Jared Hamman.
Philippou knocked Hamman to the canvas several times with well-placed punches before finishing him at 3:11 of the first round.
"It's about time," said the hard-hitting Philippou, who improved to 2-1 in UFC and earned his first knockout. "I wanted to prove I belong here."
Philippou upped his professional mixed martial arts record to 9-2 (1 no contest). Hamman fell to 13-4.
Hallman wears down Makdessi
Dennis Hallman is naturally larger than John Makdessi, and he used that superior size to quickly get the fight on the ground to earn a submission win.
The finish came at 2:58 of the first round when Makdessi got caught in a rear-naked choke and tapped.
Hallman, who has competed at welterweight and middleweight, failed to make weight for this lightweight bout with Makdessi (9-1). He weighed in at 158 1/2 pounds, and this bout was fought at that catchweight.
"I didn't want to stand up with that kid," said Hallman, who improved to 51-14-2, 1 no contest. "Luckily my game plan worked.
"I'm going to stay at 155. This fight is kind of a wash. I want to apologize to John."
Jabouin escapes with split decision
Walel Watson used his long reach to stay out of danger for most of his bantamweight bout with Yves Jabouin, but not long enough to earn a victory.
The 5-foot-6 Jabouin landed hard kicks and escaped several submission attempts to earn a split decision over Watson, who stands 5-11.
Two judges scored the fight for Jabouin 29-28 and 30-27; the third had it for Watson 29-28. ESPN.com gave Watson the edge 29-28.
Jabouin improved to 16-7, while Watson dropped to 9-3.
Bocek hands Lentz his first UFC loss
Lightweight Mark Bocek took Nik Lentz to the ground in each round and controlled the action there to come away with a unanimous decision.
The Canadian won all three rounds on the judges' cards for a 30-27 victory. ESPN.com also scored the fight 30-27 for Bocek.
Lentz (21-4-2, 1 no contest) suffered his first UFC loss, while Bocek (10-4) rebounded from a unanimous decision setback to Ben Henderson at UFC 129 in April.
Hecht elbows his way to a victory
Welterweight Rich Attonito got caught with a left elbow in the second round, and Jake Hecht jumped on him and landed punch after punch for a TKO win.
The win comes during Hecht's first appearance in UFC, and he improves to 11-2. Attonito, who won the first round by dominating on the ground, slips to 10-5.
The elbow from Hecht came as Attonito attempted to take him down. But Hecht landed two elbows, the second finding Attonito's right temple.
Attonito staggered to the canvas, and the fight was eventually stopped at the 1:10 mark.
Cholish stops Clarke in Octagon debut
It was an impressive UFC debut for John Cholish as he stopped Mitch Clarke via TKO at 4:36 of the second round.
Clarke started strong in the first round but in the second was breathing through his mouth. The fresher Cholish got the fight on the ground, where he eventually took Clarke's back.
Cholish (8-1) began punching the defenseless Clarke, forcing referee John McCarthy to wave the lightweight fight off.
Clarke loses for the first time as a pro, falling to 9-1.
Franklin McNeil covers MMA and boxing for ESPN.com. He also appears regularly on "MMA Live." Follow him on Twitter at http://twitter.com/Franklin_McNeil.