The 19-year-old stunned the tennis world when she claimed the title at Flushing Meadows last year after progressing all the way through the qualifying rounds and main draw without dropping a set.

The Briton struggled to build on those famous two weeks in New York, losing four of her next six matches including a 0-6 1-6 thrashing by Elena Rybakina at this month's Sydney Tennis Classic.

However, she put that result firmly behind her with an impressive 6-0 2-6 6-1 defeat of Stephens in her first match in the main draw of the Melbourne grand slam.

The first set was in keeping with Raducanu's US Open performance as she clinched it in just 17 minutes while dropping only four points.

But American Stephens, champion in her home slam in 2017, fought back in the second set and set up a decider with a forehand winner.

Yet the 17th seed responded well, marching into a 5-0 lead before serving out the match to set up a second-round clash with Danka Kovinic.

"I think both me and Sloane really put everything out there and gave it everything we had," she said.

"I think it was a really high-quality match, with some very long rallies. I'm very happy to come through against a great champion like her."