Ukrainian tennis player impresses reigning Australian Open champion - video

For the 25-year-old Ukrainian, it was her debut in the main draw of the Australian Open.

Keys praised Oliynykova and highlighted her strengths in her on-court interview.

“My opponent today was incredible," she said.

"She started the match really well, she’s a great competitor and she definitely made it difficult for me… It’s not a typical style you see every day, which I think makes it a little bit harder. The changes of pace with higher balls and slice, and she’s also very fast and got to a lot of balls."

“So today I really had to work on the other side of the net. I managed to do that, and I think toward the end I was able to trust myself, take a step back, and then just go for my shots,” Keys added.

The match between Keys and Oliinykova lasted one hour and 41 minutes and ended in a 6—7(6), 6—1 victory for the American tennis star.