As his greatest rival lunged in for the kill, Marquez calmly bent his knees and dipped his left shoulder before springing forward, unleashing a short, looping right hand. His fist landed squarely on the face of Manny Pacquiao, and as the great Filipino warrior dropped to the canvas, part of his legacy crumbled with him.
Pacquiao is known as the best fighter of his generation, but with the image of his motionless body firmly implanted into our memories, the perception of his career will never be the same.
Yes, he will always be known as a relentless fighter, a magnificent champion who won 10 world titles spanning eight different weight classes. But after being destroyed by a bloodied Marquez, who is six years his senior, Pacquiao's mythological status within the sport is a thing of the past.
While he was once considered the most dangerous man in boxing, Pacquiao is clearly just a shell of his former self. He's lost his last two fights, he hasn't registered a knockout in over three years, and with his most recent defeat, he can no longer claim the upper hand in the defining rivalry of his career.
Meanwhile, with one devastating punch, Marquez launched himself up the list of all-time greats. He is only the third man to knock out Pacquiao, and the first to do so this century.
He also justified the claims that he was robbed in their first three meetings, and although he trails Pacquiao 2-1-1 in their career series, he undeniably scored the most convincing victory of their rivalry.
Both men entered Saturday's fight as two of this generation's best, and the outcome wasn't going to change that. But with his brutal knockout win, Marquez will no longer play second fiddle to Pacquiao in a historical sense.