The 18-year-old came through a late wobble of nerves for a 6-2 6-3 US Open first-round win against Stefanie Vogele in New York.
In only her fourth tournament since her surprise run into the last-16 of her home Grand Slam, she said of the intervening time, “I think I have improved in the last few weeks. Playing at this level week in, week out you adapt and, if you don’t, you’re going to lose.
“I’ve come quite far in maintaining the consistency of the high level and the longer points. As the weeks have gone on and I’ve played more matches, I feel very confident in my game and taking the game to the opponent.”
Already, Raducanu’s forehand looks a more potent weapon than at Wimbledon and she did not look overawed by the occasion until the final moments when she needed seven match points to get past her Swiss opponent.
“Everyone could tell I was getting shaky at the end,” she said. “I was so relieved at the end of it. It is absolutely amazing. I feel really good physically and confident in my game. I’m exciting to see how far I can go.”
Raducanu, who had come through three qualifying rounds to make the main draw, now faces Zhang Shuai, who knocked her out of the event in San Jose earlier this month.
The teenager remains the sole Briton left in the draw after fellow qualifier Katie Boulter lost out 6-3 6-2 to Ludmilla Samsonova.