Redukanu won the first set in 38 minutes after successfully converting his only break point in the fifth game.
He then immediately broke Osaka’s service at the beginning of the second set and broke his service to take a 4–1 lead for the second time, after saving the break point in the fourth game.
With the service of Japan’s Osaka to stay in the match, Redukanu could not change his first match point in the seventh game.
But after increasing the point of another match and saving a break point, Redukanu completed the victory in the third attempt, winning the second set 6–2.
Talking to Sky Sports after the match, he said: “I felt that it was going to be a really difficult match.
“Naomi won four slams, she has been world number one, won the masters. She is very dangerous and on the hard court, I think she is particularly comfortable.
“I knew that I would have to play well and manage my own service games, which I really proud how I did. I was making some inroads in his service game, because I had a little habit of it.
“I am really happy how I handled the speed and situations of the ball in DC.”
Redukanu is due to women’s doubles action on Thursday, which is partnership in the quarter -finals against Giuliana Olmos and Aldila Sutjiadi.
