Emma Hayes got off to a winning start as United States manager with a dominant 4-0 victory over South Korea in a friendly.

Two goals each from Chicago Red Stars forward Mallory Swanson and Gotham FC defender Tierna Davidson secured the win as the four-time Olympic champions build-up to the Paris Games this summer.

At DSG Park in Colorado, Swanson put the US in front in the 34th minute - and four minutes later, they were two up thanks to a looping back-post header from Davidson.

Early in the second half, Davidson again scored with a far-post header before Swanson added a fourth in the 74th minute.

"You can see we're building something," said Hayes.

"There's lots of work to do. There's lots of holes in our play, no question, but it was a good start."

Hayes ended her 12-year stint as Chelsea boss at the end of the Women's Super League season by winning her fifth consecutive league title, her seventh in total, at the club.

The 47-year-old added she has felt "re-energised" since leaving Stamford Bridge to move into international management.

The US will face the South Korea again on Tuesday at Allianz Field in St Paul, Minnesota.