The Kiwi No 1 called it quits due to a leg injury, down 6-2, 3-0 to Romanian second seed Simona Halep.
It is the fourth time in the last five years that Erakovic has failed to reached the second round at Flushing Meadows.
Erakovic had her serve broken in the first game and it didn't get any better from there.
After losing the opening set Erakovic (27) called for the trainer to treat her right leg, something which had been troubling her prior to the match and in practice.
Whether this had been hindering Erakovic enough for her to make the 15 unforced errors in the first set compared to her opponents six is uncertain, although Erakovic did hit one more winner than Halep - seven to six.
The New Zealander was broken in the first game of the second set and then really appeared to struggle with her movement.
It didn't get much better as her Romanian opponent reeled off the next two games before Erakovic was forced to call it quits and withdraw from the match after 47 minutes of play.
"The last few days it's been doing really well and feeling good. The legs been doing well and I've been hitting the ball well. It's probably the big occasion, against someone like Halep you need a lot more of yourself," the world No 99 said.
"I just think it sprung on me in the middle of the set and it just got worse and worse and I just move well enough and compete. It's very, very disappointing."
"The injury is mainly to do with putting a load on my right knee and trying to spring from the knee. I was at the stage of thinking it was behind me and just a niggle. I just didn't think it was this bad to make me retire."
Erakovic is still scheduled to play doubles with Brit, Heather Watson later in the week.
