Below, we will give you live round-by-round updates on what's happening inside the arena.
The night's undercards are just wrapping up and in a few moments, Manny Pacquiao (54-4-2, 38 KO) and Juan Manuel Marquez (54-6-1, 39 KO) will meet again for the fourth time.
Just in case you're curious. Here are the previous results of the Pacquiao vs Marquez matches.
Pacquiao-Marquez 1: Draw
Pacquiao-Marquez 2: Split decision for Pacquiao (115–112, 112–115, 114–113)
Pacquiao-Marquez 3: Majority decision for Pacquiao (114–114, 115–113, 116–112)
Stay tuned and please wait as we give you today's main event match of Pacquiao-Marquez IV live from Las Vegas through a special round-by-round update below. Please refresh every 5 minutes to get the latest live update.
Round 1:
Both men land straights early. One-one-two from Manny falls short. JMM to the body. Marquez flurries as Manny steps in. Good left straight from Pacquiao. Marquez jabs to the body. Marquez lands a good counter left as Manny comes in. Both swing hard but hit air. Marquez hits the body, Pacquiao goes upstairs with his left. Close round; 10-9 Pacquiao in our book.
Round 2:
Again, they're waiting each other out. Pacquiao shoots in a right, then misses a left uppercut. Marquez gets in a short right. Pacquiao with a straight left, a nice punch. Marquez content to stand back. He gets in a good right. Again, Pacquiao did more work. Pacquiao wins the round for us, 10-9.
Round 3:
Left hook from Marquez. Manny with a solid jab. Good one-two from Manny and a lead left. Stiff jab. Marquez to the body. Once again. HUGE OVERHAND RIGHT FROM MARQUEZ CRUSHES MANNY! Manny's up but that was a HARD knockdown. Marquez lands it again. JMM to the body. Once again. Manny's lead left hand connects. Marquez rips to the body and they trade hard to end the round. 10-8 Marquez.
Round 4:
Marquez lands with a high left. Marquez follows with a straight right. Pacquiao not in huge hurry to engage here. Pacquiao lands a jab, but Marquez makes him eat two hard rights before the bell. Marquez wins the round, 10-9. Marquez leads, 48-47.
Round 5:
Pacquiao drops Marquez with hard left. Incredible round. Marquez takes eight count. Pacquiao is at his most dynamic, battering Marquez with set-up lefts. Hard rights. He had Marquez cornered twice and wailed on him. Pacquiao win the round, 10-8. Pacquiao leads, 57-56.
Round 6:
Big left snaps Marquez head back. Marquez missing now. Marquez's nose is bleeding and appears it might be broken. He's breathing with mouth wide open. Hard right by Marquez. Jab by Marquez. Pacquiao lands a right. Marquez follows with wicked hard right as Pacquiao was moving forward. Pacquiao's out, not moving, fight is over. Marquez wins. He runs to a corner and stands. Pacquiao down on canvas with his cornermen over him. He's now sitting up.
Marquez wins by knockout at 2:59.
Photo by Eric Jamison / Associated Press