Women's coach Teri McKeever, also Coughlin's longtime personal coach, said it was painful but ultimately "a mathematical" decision to drop the veteran. The coaches didn't just look at the swimmers' splits, but subtracted the relay exchanges and considered that number. Neal and Schmitt were the two fastest from the morning preliminaries by that measure, McKeever said.

Troy, the University of Florida coach, had a good night: In addition to Lochte's 400 IM gold, fellow Gators Elizabeth Beisel won silver in the women's 400 IM and Peter Vanderkaay won bronze in the 400-meter freestyle.

Dana Vollmer set a new Olympic record swimming her 100-meter breaststroke preliminary heat in 56.25 seconds. She and teammate advanced in the evening semifinal heats to qualify for Sunday's medal round. Brendan Hansen will advance to Sunday's 100-meter breaststroke final.

Troy said that while Lochte should have had a faster freestyle portion of the 400 IM, he was pleased that as he's grown in confidence, he takes charge of races. "He's not dictated by the field," he said.

Lochte seemed to embrace his role on top, at least for this night, saying his Twitter account that he couldn't have done it without Phelps. After the morning preliminaries, when Phelps finished an astonishing eighth to just make it to a final spot in the final, Lochte said no one should ever count him out.

"I'm going to talk to him and see how he felt about that," Lochte said.

By failing to win the 400 IM, Phelps may have missed his opportunity to become the first male swimmer to win three gold medals in the same event in three Olympics. He has two more chances for a three-peat, but another swimmer, Kosuke Kitajima, may be first to get there: He advanced in Saturday night's 100-meter breastroke race to Sunday's final.