Simona Halep revealed that she didn't play very well during her third round win over Shelby Rogers at the US Open.
The Romanian looked great on court, playing within herself and recording just nine unforced errors in the straight set win over the American during the night session at Arthur Ashe Stadium in Flushing Meadows.
However, the eleven-time WTA winner revealed that she struggled to adapt to the conditions.
"Actually today I didn't play very well," the 23-year-old told wtatennis.com.
"It was the first time I played the night session and I couldn't feel the ball at the beginning of the match – it's a big difference between playing at night and day. And the weather was cooler today – it was just really different out there.
"But after that I found the rhythm and started to be aggressive again. It was good in the end."
The world number two is looking strong in New York City as she is yet to drop a set. Now, Halep is just one win away from her first quarter-final appearance at the US Open.
Halep welcomes the good form following her disappointing first round exit at Wimbledon.
"It was a great first week for me…it was nice," she added.
"I came here without expectations, because after Roland Garros and Wimbledon, I couldn't think like I would do a good result here. But I'm in the second week now. I feel happy. I feel confident. I feel like I have chances this tournament. I'm just looking forward to the next round and, of course, improving day by day."
Waiting for Halep in the fourth round is Sabine Lisicki of Germany. The 24th seed dismantled Barbora Strycova two sets to one in her third round encounter.