Gauff is ranked 16th, closing on top American Sofia Kenin in 13th, but neither advanced to the second round on Monday.

The 17-year-old was stunned 6-4 6-2 by Wang Qiang in a sloppy display that included 38 unforced errors, with 21 in a second set in which she fell 5-0 behind.

Meanwhile, Kenin was beaten by compatriot Madison Keys, who came into the tournament in high spirits having won her sixth career title – and first since 2019 – at the Adelaide International 2. That run included a semi-final defeat of Gauff.

After her latest loss, Gauff said: "I think just everything disappointed me about today.

"I feel like in the pre-season I worked really hard, and I felt like I was ready to have a good run here. Today I just didn't perform well.

"I think there's a lot to learn from. I think I was playing a little bit tighter than normal.

"So I think next time coming into the first round of a slam, especially after a tough week before, I think I need to just play more free and focus on the moment."

Keys is playing with that freedom, eager to move on from a dismal 2021 in which she won only 11 matches.

"I'm not taking it quite as seriously, that's the biggest difference this year," she said.

Keys already has seven wins in eight matches in 2022, defeating fellow Americans in each of her past three outings.

Of the win over 2020 champion Kenin, she said: "At this point every first round is tough, but when you have to go up against a grand slam champion it's never easy.

"I think knowing that she was going to compete so well, I just had a really good mentality and attitude. I had a couple of opportunities I didn't really capitalise upon and I was able to reset and continue to play well.

"I had my first real run in a slam here, I missed last year, so absolutely ecstatic to be back in Melbourne. It would mean the world to have another run here."