Simona Halep Makes History With Her First Round Loss in the 2018 US Open

World No. 1 Simona Halep lost in the first round at the US Open Monday. She was the first player ranked No. 1. to lose in the first round in the tournament's history.

Estonia's Kaia Kanepi, ranked No. 44, beat the Romanian tennis player in two sets, 6-2 and 6-4, in the first match on the new Louis Armstrong Stadium. Halep tried to battle back and did tie Kanepi at 4-4 in the second set, but she lost in 76 minutes. Despite the loss, Halep will remain at No. 1 because of the points system.

"I think I didn't go that much anymore for my shots, and that's why it came to 4-4. I thought I have to hit more aggressive again, and I tried to do that," Kanepi said to reporters after the match.

This is the second consecutive year Halep lost in the first round of the US Open. She was ranked No. 2 when she lost last year on Arthur Ashe Stadium. Maria Sharapova beat her in three sets, 6-4, 4-6 and 6-3.

Halep thinks every player struggles in the first round because of nerves. "Even when you are there in the top, you feel the same nerves," she told reporters after her match against Kanepi. "For me, it's more difficult in the first round because I'm more emotional."

"Today was not my day," Halep said. "The balance was not there. I couldn't feel myself strong on the court to win this match."

"It's a bad day for me," she continued. "Also, she deserved to win because she was playing better than me today."

Following the match, Halep posted a message on Instagram reading, "Sometimes you win, sometimes you learn."

"She has been playing really well in the US lately, so I thought I just have to be aggressive and try to stay calm," Kanepi said in a press conference after her win. "I remembered how I played her last time. I was just trying to do the same." The two women previously played each other in 2014, and Halep won in three sets.

Halep thinks Kanepi has a good chance of going forward in the US Open. "She's a very strong player, so she has a big chance to do a great result," she said. "It's [the] second time I played against her and always I felt she has a very powerful game."

Kanepi will play Jil Teichmann from Switzerland in the second round Wednesday. Teichmann beat Dalila Jakupovic in two sets, 6-3 and 6-0, in the first completed match of the US Open earlier Monday.