Boxing: Force of nature unleashes a firestorm of punishment
They knew that the Mexican's reach would be five inches longer, that he would be four and a half inches taller and that by the time the fight began, he would be a full stone heavier.
Manny Pacquiao's fans were worried that the brilliant little Filipino had moved up one weight too many; that he was in too deep; that if he wouldn't be outclassed, he might finally be overpowered.
But by the end of 12 devastating rounds in Arlington, Texas, last Saturday night, Pacquiao had cemented his reputation as one of the greatest fighters of all time.
The man who'd begun his pro career as a 16-year-old lightflyweight weighing some 95 pounds was, at the age of 31, fighting for an unprecedented eighth world title in an eighth weight division.
The light middleweight limit is normally 154 pounds; to make the fight happen, both sides agreed to a catchweight 150lb maximum. At the Friday weigh-in, Pacquiao stepped onto the scales at 144 pounds and 6 ounces.
His opponent, Antonio Margarito, came in on the 150 limit. The skin covering Margarito's bones was as taut as a drum. He had wasted all the fat away and immediately began gorging on carbohydrates afterwards, peeling a banana and dipping it in a jar of peanut butter as he left the arena. By fight time the following night, he was an estimated 16 pounds heavier than his opponent.
Pacquiao could have come in heavier but had made a strategic decision to sacrifice bulk for speed. He wasn't going to compromise his legendary hand speed, no matter the weight of his opponent.
It has been the prime weapon throughout his career. That, and a level of power seemingly disproportionate to his frame; as if those fists, when they land, turn into rocks. The third weapon in his arsenal is the metronomic precision of his punching.
In most fighters, as in most sportsmen, speed comes at a price: technique starts to degrade the faster it is applied. The timing starts to corrode, fractional errors accumulate, precision is lost in the execution of skills.
But in Pacquiao all three elements are fused and harmonised. It is this miraculous combination of speed and power and accuracy that makes him a virtuoso of the ring.
On Saturday night, in the futuristic stadium that is the home of the Dallas Cowboys, he unfurled his repertoire.
Standing 5' 6 1/2" against Margarito's 5' 11", he was reaching up all night. It didn't matter. The Mexican held his gloves high, peeking out through a gap, and this didn't matter either.
Once Pacquiao found his groove, the straight jabs started to prise apart the gloves, driving a wedge between them, forging a pathway to the target that would become more and more open as the fight progressed and the Mexican weakened.
In the fourth round, the first serious damage was inflicted. Pacquiao unleashed what the Sky Sports commentator John Rawling called "a firestorm of punches", flurries of lefts and rights delivered with bewildering speed. After one such fusillade, Margarito was left with a gash on the cheekbone beneath his right eye and a bruise that would soon swell to bulbous proportions.
After this onslaught, he raised his gloves even higher; Pacquiao promptly sank a left to the rib cage; Margarito instinctively lowered his elbows to protect his body; Pacquiao immediately tagged him with a left and right to the face.
But Margarito, a tough, high-class operator himself, had come to fight too. He hurt Pacquiao more than once and whenever he got the smaller man on the ropes, inflicted heavy body shots.
In the fifth, they had one such encounter, the Mexican using his weight and physique to pin his opponent on the ropes and pummel him. The 41,000 crowd responded with loud acclaim and Pacquiao, having escaped the ropes, banged his gloves together, applauding Margarito's attack. He was revelling in the battle. Margarito nodded his head in reply, mutual appreciation between them.
In the sixth, he marched Pacquiao onto the ropes again, both of them trading blows in a ferocious exchange. And in the eighth, Margarito caught him with an upper cut that lifted Pacquiao's head off his chest. It should have
wobbled him, at least, given the weight differential, but Pacquiao's powerful legs soaked up the impact -- he was untroubled. This boxer, with all his extravagant talent, is gifted with phenomenal strength too.
He continued to blast Margarito with combinations, cluster bombs delivered with the rhythm and efficiency of industrial pistons: left-right-left-right, ramrod-straight and flush on the target. It was a masterclass. In the tenth, he tried to finish the fight. Margarito withstood the barrage and staggered back to his corner.
The eye was grotesque now, his face a Francis Bacon portrait of blood and suffering. The ringside doctor inspected the damage. He held up two fingers in front of the Mexican's face: how many? "Dos."
The fight continued. Pacquiao was picking him off at will now. "He may see the fingers," remarked Sky's Glenn McCrory, "but he's not seeing the punches." At one point in the 11th, Pacquiao backed off an attack and looked at the referee, signalling to him to end the contest.
He said afterwards that he hadn't wanted to inflict any more punishment.
Those who know him say he is a lovely man. In a boxing ring, he is the complete fighting machine.