Australia are none from two early on day one of the US Open following first-round exits for Casey Dellacqua and Matt Ebden.

Unable to replicate her fine run to the fourth round last year, Dellacqua went down 7-5 6-2 to Estonian qualifier Anett Kontaveit, while Bulgarian 17th seed Grigor Dimitrov outclassed Ebden 6-4 6-2 6-4.

Dellacqua faces a rankings dip after being unable to defend the truckload of points accrued in 2014, but was philosophical in defeat.

“I didn’t take any of last year’s results into today’s match. It’s a new year. Every tournament you play is a new tournament,” she said.

“I came up against a girl that was full of confidence coming through qualifying, playing well and unfortunately I didn’t bring my best stuff.

“You never take qualifiers lightly because they’re really tough, and she’s young.

“She’s 20, she’s got nothing to lose, she was going to throw the kitchen sink at me and she did – and she did it well.

“Credit to her.”

A big underdog against Dimitrov, Ebden was unable to match the former Wimbledon semi-finalist from the back of the court and crashed out after one hour and 33 minutes.

Three other Australians are scheduled for singles action on the opening day at Flushing Meadows.

Sam Groth plays Alexandr Dolgopolov, John Millman is also up against Ukrainian Sergiy Stakhovsky and Daria Gavrilova faces Russian teenager Daria Kasatkina, who gained a late entry following the injury-enforced withdrawal of third seed Maria Sharapova.