Osaka tosses racket, overcomes test from teenager at U.S. Open

Novak Djokovic, of Serbia, falls during a play against Jan-Lennard Struff, of Germany, during the third round of the U.S. Open tennis championships, Friday, Sept. 4, 2020, in New York. (AP Photo/Frank Franklin II)

Naomi Osaka, of Japan, walks off the court after winning a match against Marta Kostyuk, of the Ukraine, during the third round of the US Open tennis championships, Friday, Sept. 4, 2020, in New York. (AP Photo/Seth Wenig)

NEW YORK — Naomi Osaka spiked her racket after one errant forehand late in the second set at the U.S. Open, then flung it the length of the baseline after a missed backhand return ceded that tiebreaker.