NEW YORK—For the second straight year, the first round was the final stop for Simona Halep.

Kaia Kanepi swept Halep, 6-2, 6-4, sending the world No. 1 crashing out of the US Open opening round for the second straight year and third time overall.

More: Kanepi Shocks Halep

Halep, who fell to five-time Grand Slam champion Maria Sharapova in round one last year, suffered her 12th opening-round Grand Slam exit.

The Roland Garros champion says there's a simple for first-round stumbling blocks: nerves.

"I think every player is struggling a little bit in the first round," Halep said. "It's always about the nerves. Even when you are there in the top, you feel the same nerves. You are human. So it's the same thing."

The 26-year-old Romanian said she's more vulnerable in major openers because she's more stressed.

"For me, it's more difficult in the first rounds, because I'm more emotional," Halep said. "That's why I need a good start. But I'm not scared about that. I have won so many first rounds and also tournaments after tough first rounds. So I'm not focusing on that, but sometimes can happen, and today happened. It's nothing. It's not a drama, but it's tough."

The noisy hustle and bustle of New York can leave the self-described "quiet person" feeling a little bit overwhelmed. 

"Maybe the noise in the crowd, the city is busy," Halep said. "So everything together. I'm quiet person, so maybe I like the smaller places.

"But I did great results here. I'm not complaining. I just say that I don't really feel 100 percent my game when I step on the court here. But maybe in the future it's gonna change something, I will change something and it will be better."

Photo credit: Rogers Cup