Start spreading the news: Stars hassled by New York hustle

Crowded out: Simona Halep plays Kaia Kanepi

Start spreading the news: New York may be the city that never sleeps, but the likes of Simona Halep and Garbine Muguruza wish it would occasionally just take a nap.

World number one Halep won a maiden Grand Slam at the French Open this year.

However, on Monday, the Romanian slumped to a 6-2, 6-4 defeat to Kaia Kanepi at the US Open, becoming the first top seed to lose in the first round of the tournament in the modern era.

"The city is busy. I'm a quiet person, so maybe I like the smaller places," said the 26-year-old who was also overwhelmed in the first round last year by Maria Sharapova.

"I'm not complaining. I just say that I don't really feel 100% 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."

Former Roland Garros and Wimbledon champion Garbine Muguruza sympathised with Halep even if the Spaniard survived her first round outing on Monday.

"I really feel her way when she says that, because me, at the beginning, for the first four years, I didn't go through almost the first round," said the 24-year-old who only made the second week at Flushing Meadows for the first time at the fifth attempt last year.

"I didn't really understand what was happening -- the city, the people. But I'm learning to handle that better because I really want to go far in the tournament.

"It's black or white a little bit."

For Muguruza, the answer to her city stress is a healthy supply of Netflix viewing when she's holed up in her hotel in Manhattan.

That way she keeps her outings onto the streets of New York -- home to 8.5 million people -- to a minimum.

"There is a lot of people, there is a lot of noise. I always try to be in calm places," admitted the Spaniard after her 6-3, 6-0 win over China's Zhang Shuai.

"I'm happy to go to the park, but I don't do a lot of shopping. I don't walk around the city. I feel people are going to walk over me. It's like, Man, seriously."

For small-town Estonian girl Kanepi, whose capital Tallinn boasts a more modest population of 420,000, New York has always been a welcome eye-opener.

"I love being in New York. And I like the weather: humid and hot," said the 33-year-old, two-time quarter-finalist, who hails from a country which sees temperatures stay stubbornly below zero for four months every winter.