The UFC's greatest feuds

One of the things that marks mixed martial arts fighters is the respect they almost always show for each other and for the sport. They frequently thank their opponents for taking the fight and often express that they feel it is an honor to meet a particular fighter.

But every now and then, in a combat sport, feelings get heated and it leads to feuds. The Ultimate Fighting Championship has had a series of memorable feuds which the men settled in the cage.

No feud ever had the heat that the one between veteran Ken Shamrock and Tito Ortiz brought. Shamrock was a former WWF wrestling star, but his dislike for Ortiz was very real.

Shamrock, one of the earliest UFC stars, felt Ortiz had disrespected two of his Lion's Den fighters, Jerry Bohlander and Guy Mezger, after Ortiz had beaten them. After knocking out Mezger at UFC 19 on March 5, 1999, Ortiz pretended to dig a grave in the center of the cage.

That infuriated Shamrock, who had to be restrained from going after Ortiz.

When casino moguls Lorenzo and Frank Fertitta and partner Dana White bought the UFC in 2001, one of the first things they did was to attempt to put on a Shamrock-Ortiz fight.

They met for the first of three times at UFC 40 on Nov. 22, 2002, at the MGM Grand Garden in Las Vegas in what was the first mega-event in company history.

Each of their fights was a major event and it was clear it was the top feud in UFC history. The Yahoo! Sports MMA staff unanimously voted it the promotion's top feud.

List compiled by Kevin Iole, Dave Meltzer and Dave Doyle. Only numbered major UFC events were considered for this list. Thus, Ultimate Fight Night and Ultmate Fighter Finale events were not considered.

1. Ken Shamrock-Tito Ortiz: Prior to their first fight at UFC 40, Shamrock became so enraged at something Ortiz said at a news conference that he hurled a chair at him. They had to be kept apart by security because neither man would back off. Ortiz stopped Shamrock in the third round at UFC 40. They then coached against each other on Season 3 of "The Ultimate Fighter," setting the stage for a bout at UFC 61. Referee Herb Dean stopped that bout in the first round as Ortiz cracked Shamrock with an elbow. That enraged the crowd, so White ordered a rematch and the men met again on an Ultimate Fight Night card. Ortiz again dominated and stopped Shamrock in the first, putting an end to their bitter rivalry.

2. Chuck Liddell-Tito Ortiz: Ortiz won the UFC's light heavyweight championship and was gaining acclaim as a star as the UFC moved into its modern era. Liddell was one of his training partners and wanted a fight against the champion. Ortiz said no and said the two were friends and had an agreement they'd never fight. Liddell insisted it wasn't the case. They met twice, at UFC 47 and UFC 66, with Liddell dominating each time. He stopped Ortiz in the second round at UFC 47 and in the third at UFC 66, which became the first event to exceed a million pay-per-view buys.

3. Ken Shamrock-Royce Gracie: Gracie was the 175-pound Brazilian whose jiu-jitsu expertise made him the biggest star of the UFC's early days. Shamrock was the only man in those days who seemed to have any clue how to fight a jiu-jitsu fighter. But Gracie, en route to the UFC 1 tournament title, choked out Shamrock with the Gi. Shamrock, a fierce competitor, demanded a rematch and got it in a Super Fight at UFC 5, but they fought to a time-limit draw.

4. Matt Hughes-Matt Serra: Each man held the welterweight title, but it was Hughes' reaction to Serra's title-winning knockout of Georges St. Pierre at UFC 69 that set off their rivalry. Hughes was to fight the winner, which was expected to be St. Pierre, and was seated at ringside to watch. But when Serra landed a big punch and became the most improbable champion in UFC history when he knocked St. Pierre out, the cameras turned to Hughes for his reaction. He grinned and Serra took it as an insult. They coached against each other on Season 6 of "The Ultimate Fighter" and Serra continually jabbed at Hughes with verbal assaults, frequently referring to him with a derogatory term that describes the male anatomy. They eventually met at UFC 98 in a much-delayed bout and Hughes eked out a disputed split decision victory.

5. Matt Hughes-Frank Trigg: After a successful stint in the now-defunct World Fighting Alliance, Trigg signed with the UFC and immediately got a shot at the title, then held by Matt Hughes. Hughes retained the belt, winning by rear naked choke at UFC 45. But Trigg, who would become a TV broadcaster and Internet personality, kept insisting he was the better fighter. Hughes didn't feel he had anything to gain by fighting Trigg again, but they finally hooked up at UFC 52. In one of the great fights in UFC history, Hughes broke free of a rear naked choke, carried Trigg across the cage and slammed him violently to the mat. The crowd erupted, Hughes pounded on the ground and finished with a choke of his own.

Honorable mention: B.J. Penn-Jens Pulver, Wanderlei Silva- Quinton Jackson, Frank Shamrock-Tito Ortiz.