Chase Kalisz swims to gold, earns Team USA's first medal in Tokyo

American swimmer Chase Kalisz has won the USA's first swimming medal in Tokyo, holding off teammate Jay Litherland to take gold in the Men's 400m individual medley.

Team USA's second medal followed closely behind when Litherland touched to secure silver.

NBC Olympics reports Kalisz, part of a crop of young guns charged with carrying on the legacy established by Michael Phelps, the most-decorated swimming Olympian in U.S. history, was among the favourite going into the Games, and he did not disappoint.

The 27-year-old grabbed the lead on the first length of the backstroke after France's Leon Marchand had led after the butterfly leg and never looked back.

He battled with New Zealand's Lewis Clareburt through the breaststroke but the Kiwi faded badly in the freestyle and finished seventh.