Kate Middleton

Duke it out with the Duchess! Naomi Watts and Kate Middleton both looked stunning and sweet in the same white dress by Zimmermann -- but the Duchess of Cambridge slightly tweaked her overall look with classic accessories at the prestigious Sydney Royal Easter Show on Good Friday, April 18.

PHOTOS: See all of Kate's looks from the 2014 Royal Tour!

Rocking identical white, three-quarter-sleeve eyelet dresses by the Australian label, Watts and Middleton's accessories and hairstyles made all the difference in their overall looks.

The Duchess, 32, opted for a nice silver wristwatch on her left arm, which called attention to her sparkling engagement ring. She paired the spring-appropriate outfit with simple pearl drop earrings, and left her straight brunette tresses down.

PHOTOS: The adorable Aussie and New Zealand royal tour of 2014!

Watts, 45, looked flawless in the white lace dress for her Jacobs Creek Wine ad campaign. In a campaign pic from the libations brand, Watts nurses a glass of white wine while surrounded by gorgeous vineyards. The photo of the British-Aussie star was taken in the Barossa Valley, one of the Australia's oldest wine regions. The star looks more casual than the Duchess, with a brown leather bracelet on her wrist and her blonde locks styled into beachy waves.

PHOTOS: Get Kate's style for less!

What's most interesting about this fashion face-off is Watts' role as the late Princess Diana in the 2013 biopic, Diana.

Who wore the look best: Kate Middleton or Naomi Watts? Vote now!