Manny Pacquiao vs. Juan Manuel Marquez and the Top Series of All Time

The series between Juan Manuel Marquez and Manny Pacquiao was compelling before they met for a fourth time in Las Vegas.

The two fighters have always fought with heart, determination and skill, and that has resulted in exciting bouts for boxing fans.

When Marquez registered a sensational knockout Dec. 8 and won his first bout in the series, that elevated the Pacquiao-Marquez rivalry to exalted status in boxing annals.

Here's a look at the top seven boxing series in history.

7. Micky Ward vs. Arturo Gatti

The three-fight trilogy between Micky Ward and Arturo Gatti was one of the most action-packed and thrilling in boxing history.

Ward and Gatti were not champions, but these two super featherweights fought with a fervor not often seen.

They fought three times in 2002 and 2003. The first fight was a close decision won by Ward by a majority decision. Gatti won the next two fights by unanimous decisions.

Both fighters were willing to eat their opponent's punches in order to deliver their own. The punishment was extreme and took a lot out of both fighters.

However, both demonstrated remarkable passion when they fought each other.

6. Tony Zale vs. Rocky Graziano

Tony Zale was a two-time middleweight champion of the world. He was one of the greatest punchers in his weight class in the history of the sport.

He engaged in a three-bout trilogy with Rocky Graziano between 1946 and '48. In the first bout, Zale registered an early knockdown, but Graziano rallied and took charge in the fight. He looked like he was about to knock out his rival, but Zale turned the tables with a sixth-round knockout.

In the 1947 rematch in Chicago, Zale dominated the fight in the early rounds, and it looked like Graziano was about to get knocked out. This time, Graziano reversed the trend and registered a sixth-round knockout.

In the third and final bout in '48, Zale went to New Jersey to take on Graziano. In the third round, he drove a hard right to Graziano's body and then followed with a left hook to the jaw. Graziano got knocked unconscious by the combination, and the memorable series came to an end.

5. Joe Louis vs. Max Schmeling

The two fights between Joe Louis and Max Schmeling were among the most memorable and shocking bouts in boxing history.

In 1936, Louis was the up-and-coming star of the heavyweight division. He seemed like an indestructible fighter, and he seemed to have a big advantage over Schmeling. However, Schmeling used his jab to keep Louis away, and he landed a hard right hand in the fourth round that knocked down Louis and hurt him badly.

Schmeling built up a huge advantage and then knocked him out in the 12th round, shocking the boxing world.

The two men met in a famous rematch in 1938. With the Nazi party looking for world domination under Adolf Hitler, Schmeling became a reluctant symbol for the murderous regime.

In truth, Schmeling was neither a Nazi nor a Nazi sympathizer, but he was portrayed as the villain. Louis was not only fighting for revenge over the man who had knocked him out; he was fighting against Nazi tyranny.

Louis was also a symbol and hero of African-Americans, who had few public figures to look up to at the time. When the two men took to the ring in Yankee Stadium, Louis was more prepared to fight than he had ever been in his life.

In the opening seconds, Schmeling landed a hard right that triggered a brutal response from Louis. He hit Schmeling with a series of power punches that caused the German to scream in pain. Louis knocked down Schmeling several times in the round, and referee Arthur Donovan stopped the fight after a little more than two minutes of action.

4. Sugar Ray Leonard vs. Thomas Hearns

Thomas Hearns and Sugar Ray Leonard met in an epic bout in 1981 to unify the welterweight championship. At the time, Hearns was 32-0 and Leonard was 30-1.

This fight commanded the attention of the American sporting public like no bout since Muhammad Ali and Joe Frazier fought in the Thrilla in Manila in 1975.

Going into the fight, Leonard was perceived as the speedy boxer, while Hearns was considered the devastating knockout artist. Throughout much of the fight, Hearns' boxing skill gave him the edge, but Leonard unleashed a furious late-round assault and came away with a 14th-round TKO.

The rematch did not occur until 1989. While both fighters were no longer at their best, they were still highly skilled. Hearns knocked down Leonard twice and appeared to win the fight. However, the fight was ruled a draw, and the controversial decision angered Hearns' fans.

3. Manny Pacquiao vs. Juan Manuel Marquez

Manny Pacquiao and Juan Manuel Marquez began their classic rivalry in 2004.

In the first fight, Pacquiao knocked down Marquez three times in the first round and appeared to be on his way to an easy victory. However, Marquez rallied and earned a draw.

In the next two meetings in 2008 and 2011, Pacquiao earned controversial victories. Pacquiao earned a split decision in '08 and a majority decision in '11. Both bouts were action-filled and close.

The two decided to fight for a fourth time in 2012. Both men were looking for the knockout so there could be no controversial decision left to the judges.

The heavily muscled Marquez landed an overhand right in the third round, and Pacquiao went down hard. He got up and then reversed the momentum in the fight. Pacquiao knocked down Marquez in the fifth round and landed a series of nasty punches that bloodied Marquez.

However, just when it looked like Pacquiao was getting close to taking out Marquez, the tables were turned. Pacquiao got careless and ran into a brutal straight right hand from Marquez (source: ESPN.com). The punch resulted in a brutal knockout.

A fifth fight between the two may be on the horizon.

2. Sugar Ray Robinson vs. Jake LaMotta

Sugar Ray Robinson is considered by many of the boxing cognoscenti to be the greatest professional pound-for-pound fighter in the history of the sport.

Jake LaMotta was a solid warrior with brutal punching power, but he was not in Robinson's class as a fighter.

However, when Robinson and LaMotta met in the ring, they always produced compelling fights.

They met five times between 1942 and 1945. In the first fight, LaMotta knocked Robinson down, but he got up to win a unanimous decision.

In the second fight, LaMotta dominated the fight and won a unanimous decision. The loss was Robinson's first of his career.

Robinson won the final three fights, all by decision. The last of those was a very controversial split decision that Robinson called the toughest fight of the series (source: BoxRec.com).

1. Muhammad Ali vs. Joe Frazier

Muhammad Ali and Joe Frazier met in a three-fight series between 1971 and 1975.

The first fight was among the most hyped sporting events of the last half of the 20th century.

Both were undefeated fighters, and Ali was coming back to attempt to reclaim the heavyweight title that had been stripped when he refused military induction.

Ali was the classic boxer and Frazier the powerful slugger. The two went back and forth for 14 rounds, and Frazier appeared to have a small edge. In the 15th round, Smokin' Joe decked Ali with a smoking left hook. Ali got up from the brutal shot, but Frazier won the decision.

They met again in 1974 after Frazier had lost his heavyweight title to George Foreman. This time, Ali won a close decision.

In the final bout of the series, Ali and Frazier fought in the Philippines in 1975. The bout, called the "Thrilla in Manila," saw both fighters dish out and take tremendous punishment.

Ali started out the fight in top form, and he used his jab and sharp punching to take an early lead. However, in the middle rounds, Frazier used his power punches to brutalize Ali. Somehow, Ali managed to stay upright.

In the later rounds, Ali's punches had closed Frazier's eyes, and he could not see. Frazier's manager Eddie Futch would not allow him to come out for the 15th round, and an exhausted Ali won by TKO.