RIO DE JANEIRO (Reuters) - Olympic champion Nathan Adrian of the United States powered through to the men's 100m freestyle final with the fastest time of 47.83 seconds on Tuesday after only just making it out of the heats.

Adrian came through in an outside lane to pip Australian Cameron McEvoy, who swum 47.93 and American Caeleb Dressel in 47.97.

"People that are just stoked on USA -- it makes me so proud," said Adrian, who added the outpouring of support felt "a little bit like" the U.S. was the home team.

In a tight second semi-final, Kyle Chalmers of Australia touched first in 47.88, ahead of Santo Condorelli of Canada who had the same time as McEvoy.

World champion Ning Zetao of China failed to qualify for the final.

There were huge cheers from the home crowd in Rio when the scoreboard showed that Brazilian Marcelo Chierighini had taken the last spot for Wednesday's final in eighth place.

(Reporting by Mark Trevelyan/Alan Baldwin; Editing by Greg Stutchbury)