"A lot of pressure, a lot of expectation but I can always continue to learn." Olympic gold medallist Monica Puig looked to the positives following her shock first-round loss at the US Open.

Queen of singles at Rio 2016 more than a fortnight ago, the golden girl came crashing back down to earth on Monday, upstaged 6-4 6-2 by Zheng Saisai in New York.

Puig dispatched of world number two Angelique Kerber to win gold at the Games in Rio but she was unable to replicate that performance in the first round of the season's final grand slam, broken four times as she tallied 28 unforced errors.

"It's always a little bit tough, especially coming off winning the Olympic gold medal," Puig told reporters. "A lot of pressure, a lot of expectation, but I can always continue to learn. That's what I'm going to try and do.

"All credit to her, though. She played well. She complicated me just enough. But, you know, I'm still learning. I'm still growing. Trying to find the positives out of everything."

The 22-year-old Puerto Rican added: "I've never been here before. These are new waters for me, new territory. I'm going to have to start getting used to it. Once it starts becoming a little bit more of a habit, then I'll feel comfortable.

"It took me a while to be comfortable being in the top 50, the top 30, all this stuff. It's always a process. I'm just going to have to keep learning and just take it day by day."