Sept. 4 (UPI) -- Top-seeded Novak Djokovic remained perfect this year and advanced to the fourth round of the U.S. Open with a straight-sets win over Germany's Jan-Lennard Struff on Friday in Queens, N.Y.
The Serbian beat Struff 6-3, 6-3, 6-1 in one hour and 43 minutes, holding serve throughout. Struff managed only four break points and couldn't convert.
Djokovic has earned victories in his last 29 matches and holds a 26-0 record this season. The three-time U.S. Open champion plays No. 20 seed Pablo Carreno Busta in the next round.
Earlier Friday, 12th-seeded Denis Shapovalov rallied late in the fourth set to beat 19th-seeded American Taylor Fritz 3-6, 6-3, 4-6, 7-6 (5), 6-2. No. 5 seed Alexander Zverev also advanced to the fourth round with his win over 32nd-seeded Adrian Mannarino.
On the women's side, No. 4 Naomi Osaka beat Marta Kostyuk 6-3, 6-7 (4), 6-2 by taking the final five games at Flushing Meadows. Before and after her third-round match, Osaka wore a mask in honor of Ahmaud Arbery -- a Black man who was fatally shot after being pursued by armed White men in Georgia.
For each match in the tournament, Osaka has worn a different mask in memory of a victim of racial injustice. She previously honored Breonna Taylor in the first round and Elijah McClain in the second.
"None of these deaths had to happen," Osaka said. "For me, I just want everyone to know the names more."