ROSEMONT, Ill. (AP) -- Erik Morales didn't have to wait for the result to be announced. Win or lose this was it, and although he did not make history, he did go out in style.
WBC lightweight champion David Diaz denied Morales in his bid to become the first Mexican to win world titles in four weight classes with a thrilling unanimous decision on Saturday night.
Morales, an almost certain Hall of Famer, then retired before the winner was announced.
"This is it," said Morales, who had said he would fight once more in his hometown of Tijuana if he won Saturday. "I'm not going to fight anymore. I've taken far too many punches, particularly to the head area. Punches to the head are really beginning to bother me. Diaz is a very strong fighter."
Diaz (33-1-1) had Morales (48-6) against the ropes after a flurry late in the 12th round, but Morales countered. The crowd rose to its feet, and Diaz poured it on again, sending the challenger against the ropes and whipping the fans into another frenzy as the bout came to a finish.
Judge Herminio Cuevas scored it 114-113, Robert Hecko had it 115-113 and Nobuaki Uratani had Diaz winning 115-112.
It was a thriller from the start. The fighters wasted no time tearing into each other.
Diaz, a Chicagoan making his first defense, had his opponent against the ropes in the opening round and was throwing lefts and rights when, out of nowhere, Morales sent the champion to the canvas with 11 seconds left. That drew a loud reaction from the large contingent of Mexicans among the crowd of 9,735.
Diaz returned the favor in the second, knocking down Morales with a left uppercut.
It was an intense, physical start to a bout between a fighter trying to make history and another looking to cement his status as a champion.
"Did I earn it today?" Diaz asked, his right eye swollen and black and blue.
Diaz landed a shot to the face with about a minute left in the seventh and was pounding away at Morales' midsection as the bell sounded. And Morales spent much of the eighth on the ropes before slugging it out late in the round.
They continued to go at it over the final rounds, with no let up for either.
"This was my championship fight," Diaz said. "A lot of you guys had written this was given to me, so ... now I can call myself a champion and be very proud of it."
The 31-year-old Diaz had not fought since rallying for a 10th-round technical knockout over Jose Santa Cruz last August to become the mandatory challenger for the belt. The WBC stripped Joel Casamayor of the belt, making Diaz the champion.
Morales barely made weight, checking in Friday at an even 135, but he gave Diaz all he could handle.
"He came and we did it, and thank God we had a never-quit attitude," Diaz said. "We knew that was how we had to fight. There was no other way to do it. ... The first round, when he knocked me down, it was a nice little (shot)."
Morales is going out with losses in five of his final six fights -- along with a long list of accomplishments. There were classic fights with Marco Antonio Barrera and Manny Pacquiao, and there was a procession of championships that started with his win over Daniel Zaragoza for the WBC super bantamweight title in 1997.
Morales beat WBO champion Marco Antonio Barrera in a unification bout in February 2000 and took the WBC featherweight title from Guty Espadas two years later. He became a three-division champion when he beat Jesus Chavez for the WBC super featherweight belt in February 2004, and he defeated IBF super featherweight champion Carlos Hernandez five months later to unify their 130-pound titles.
But he had dropped four of five heading into Saturday's bout, starting with a majority decision loss to Barrera in November 2004. The lone win during that stretch was an unanimous decision over Pacquiao, who beat Morales twice in 2006 -- on a 10th-round technical knockout that January and then a third-round knockout in November.
The 30-year-old Morales was adamant he had enough left to get the job done against Diaz. He said he stayed too long at 130 pounds, that he should have moved up after the first Pacquiao fight, and he also blamed his troubles on his decision to veer from his usual training routine. For this bout, he went back to working out in the mountains of Mexico after preparing for recent fights in Los Angeles.
It helped -- but not enough to make history.
"Erik is a champion," Diaz said. "He stood up to what I had to give him."