Michael Phelps and the U.S. 400-meter medley relay team closed the fastest meet in swimming history with an appropriate finish Sunday night-the 43rd world record.

Phelps earned his fifth gold medal of a world championships that showed he's still got plenty of motivation, even after winning a record eight times at the Beijing Olympics.

Swimming the butterfly leg, Phelps helped the U.S. pull away from Germany and Australia to win in 3 minutes, 27.28 seconds. That easily broke the mark of 3:29.34 set by the Americans at last summer's Olympics.

"That relay brings out the best in me," Phelps said. "That's sort of what competing does. It doesn't matter how much energy I have, it's all going to go into every race. That's one of the things that I enjoy most-stepping out onto the blocks no matter what kind of shape I'm in."