Mayweather's five key fights

To date, Floyd Mayweather's stiffest test came against Jose Luis Castillo, right, in April 2002. AP Photo/Jerry Henkel

A look at five pivotal fights in Floyd Mayweather Jr.'s career:

Pro fight No. 18
Opponent: Genaro Hernandez (38-1-1)
Date: Oct. 3, 1998, Las Vegas
Result: Mayweather by TKO in 8
Why it matters: Mayweather, at 17-0, was challenging for his first world title (WBC super featherweight) and was so cocky that he wore a WBC championship patch on his trunks into the ring. After an awkward slip to the canvas in the first round, he let his hands do the talking. He hit "El Chicanito" from all angles with hard jabs, left hooks, straight rights and uppercuts. Hernandez was against the ropes for stretches of Round 5 while Mayweather targeted openings, and a hard right uppercut rattled Hernandez's jaw. Hernandez tried luring Mayweather into traps, but the traps never sprung. In the seventh, Hernandez tried to bull forward, placing his head in Mayweather's chest. But Floyd was faster on the inside too, with hard, short hooks and uppercuts. Hernandez's corner -- led by his brother Rudy - was ready to give him one more round to turn things around after the seventh. He didn't. After the eighth, the champion's corner threw in the towel. The emotional Mayweather, winner and new champ, sank to a knee and cried.

Pro fight No. 25
Opponent: Diego Corrales (33-0)
Date: Jan. 20, 2001, Las Vegas

Result: Mayweather by TKO in 10
Why it matters: At various times during this spectacle, the TV announcers compared Mayweather to Sugar Ray Leonard, Pernell Whitaker, Willie Pep, Muhammad Ali, and Tiger Woods. All Mayweather did was dismantle a world-class, undefeated tough guy. Corrales disastrously walked forward without punching enough, and Mayweather punished him. Mayweather's jabs, right-hand leads and explosive left hook lasered in on Corrales. In the 7th, Mayweather connected with a left hook that scored the first knockdown -- and he unleashed two more left hooks before Corrales hit the floor. Another mammoth left hook put Corrales down later in the round, and a barrage in the corner put Corrales down a third time. In that insane seventh, Mayweather connected with 78 percent of his shots -- 39 out of 50. Corrales threw five punches and landed three. Midway through the 10th, Mayweather caught Corrales with a tight left hook and sent him down again, and not long after that, a straight right banged a wobbly Corrales to a knee yet again. Corrales' father-trainer Ray Woods threw in the towel, and Corrales choked back tears over the stoppage in a postfight interview, as if he could have won. But in no round did Corrales land as many as 10 punches.

Pro fight No. 28
Opponent: Jose Luis Castillo (45-4-1)
Date: April 20, 2002, Las Vegas
Result: Mayweather by decision in 12
Why it matters: Some believe this was Mayweather's only loss, though the judges who awarded him a unanimous decision are the ones who mattered, and Mayweather went to 28-0. Still, the way Castillo pressured Mayweather against the ropes was a blueprint for how to get at him. That's where punchers Jesus Chavez and Gregorio Vargas -- and Oscar De La Hoya -- have succeeded in landing head shots on Mayweather, threading shots between his shrugged left shoulder and a right glove held close to the cheek. Ricky Hatton ought to watch this tape. Castillo charged in low, aiming body shots and moving well. Mayweather landed uppercuts and other punches as Castillo advanced, but Castillo kept coming. By the seventh, it became a cat-and-mouse game: Castillo pressing Mayweather back to the ropes, Mayweather squirming and punching to escape, trying to keep the action in the middle of the ring. It got rough. Each fighter was penalized a point in the late rounds for a foul. By the 12th, Castillo was still slugging and seemed to have scored the more effective blows. In total, he landed 107 more "power" punches than Mayweather. But the judges gave a lopsided decision to Mayweather, who won their rematch more decisively.

Pro fight No. 34
Opponent: Arturo Gatti (39-6)
Date: June 25, 2005, Atlantic City
Result: Mayweather by TKO in 6
Why it matters: This one mattered to Mayweather because it mattered to sports fans, establishing him as a pay-per-view attraction as he pounded the TV-friendly Gatti into mincemeat. Gatti and trainer Buddy McGirt supposedly had a plan. Gatti came out jabbing and feinting from a distance. But a referee error took him out of the game. With the fighters in a clinch, ref Earl Morton yelled "Stop punching!" to order the fighters to break. But he didn't step between them, and as Gatti stepped back, Mayweather cracked him in the cheek with a left hook. As Gatti turned to the referee to complain, Mayweather unloaded a bigger hook to Gatti's temple that put him down. In the corner, McGirt implored Gatti: "Don't let that take you off your game plan." But it did. Gatti turned to slugging wildly and stiffened defensively. Mayweather unleashed ferocious combinations. One brutal sequence from Mayweather -- straight right, left hook, straight right, left hook, straight right -- all before Gatti could move his head out of the way. After Round 6, with Gatti's eyes swollen to slits, McGirt stopped the fight. Gatti had landed 17 percent of his punches, compared to 57 for Mayweather.

Pro fight No. 38
Opponent: Oscar De La Hoya (38-4)

Date: May 5, 2007, Las Vegas
Result: Mayweather by split decision in 12
Why it matters: If more of the world's biggest megafight had gone like its final 10 seconds -- with both men slugging toe-to-toe in center-ring -- it would have lived up to the extraordinary hype. As it was, Mayweather-De La Hoya still stands as an epic despite its lack of blockbuster action, as the best matchup of pure boxing skills that we may see in our lifetime. Mayweather won a belt in his fifth weight class (154 pounds) in what has become his customary late-career manner: starting slow, eventually outboxing his dazzled opponent and doing enough to win the decision. De La Hoya came on first, backing Mayweather to the ropes when he could, working behind his jab and frantic two- and three-punch combinations. Some shots landed. Floyd's defense seemed vulnerable. Then Mayweather woke up. Toward the end of Round 5, he landed two hard left-right combinations. His defense tightened too, and he began to elude De La Hoya's outbursts more easily. In Rounds 9 and 10, Mayweather began landing single lefts and rights. He nailed De La Hoya with a hard right to end the 10th and twice in the final round backed De La Hoya up with hard shots. It was close, but Mayweather beat the best boxer of his time, and he claimed that title too.

Don Steinberg, a winner of the Boxing Writers Association of America's award for best column in 2005, covers boxing for The Philadelphia Inquirer.