Beijing - LaShawn Merritt backed his talk with the run of a lifetime Thursday morning, defeating rival and world champion Jeremy Wariner to win gold in the 400 meters.

Merritt and Wariner split their last four events in head-to-head competition but it would be the former ECU Pirate who would stand tall in the biggest run of his life.

Merritt took gold with a personal-best time of 43.75 seconds. Wariner, the silver medalist, was nearly a second back at 44.74.

David Neville dove across the finish line to complete a U.S. sweep.

"I felt good in the semis," Wariner said. "My final wasn't that good of a race. I don't know what's happening right now"

"This is the greatest moment of my career" a winded Merritt would say.