19-Year-Old Naomi Osaka Upends Defending U.S. Open Champ Angelique Kerber

19-year-old Naomi Osaka sent the defending champ packing at the US Open on Tuesday.

When the 2017 U.S. Open draw came out on Friday, defending champion Angelique Kerber's first round match was highlighted and circled on a lot of draw sheets. On Tuesday, Japan's Naomi Osaka proved why. 

Under the roof on Arthur Ashe Stadium on a rainy day at Flushing Meadows, 19-year-old Osaka out-played the two-time Grand Slam finalist, winning 6-3, 6-1 in just over an hour to advance to the second round. The victory marked Osaka's first top 10 win of her career.

UPSET ALERT:@Naomi_Osaka_ takes out defending #USOpen champion, 6th seed Angie Kerber.

Did you see that one coming?! pic.twitter.com/dtCQifGR3L

— US Open Tennis (@usopen) August 29, 2017

After retiring with an abdominal injury in Toronto earlier this month, World No. 45 Osaka hoped to be healthy for the final major of 2017. A year ago at the U.S. Open, Osaka led Madison Keys in a third round match on Arthur Ashe but was unable to close. ​On Tuesday, Osaka simply out-hit Kerber, blasting winners all over the court and putting any memories of last year's disappointing U.S. Open exit behind her. Osaka finished with 22 winners and 17 unforced errors to Kerber's nine winners and 23 unforced errors.

Kerber is only the second U.S. Open women's champion in the Open Era to lose in the first round the following year (Kuznetsova, 2005). After reaching No. 1 a year ago when she won her second Grand Slam of the year in New York, Kerber has not won a tournament since her victory at the 2016 U.S. Open. The German also lost in the first round at the French Open in May and bowed out in the Round of 16 at both the Australian Open and Wimbledon this year. 

With Tuesday's loss, Kerber, who was seeded sixth at the U.S. Open, will drop out of the top 10 in the WTA rankings.