By HOWARD FENDRICH
AP Tennis Writer
NEW YORK (AP) — Spanish teenager Carlos Alcaraz has beaten No. 3 seed Stefanos Tsitsipas in five sets at the U.S. Open to reach the fourth round of a major for the first time. Another 18-year-old also produced a big win when Leylah Fernandez of Canada upset defending champion Naomi Osaka on Friday night. After her loss, Osaka said she is thinking about taking another break from tennis. Alcaraz’s 6-3, 4-6, 7-6 (2), 0-6, 7-6 (5) victory made him the youngest man in the fourth round at Flushing Meadows since Pete Sampras and Michael Chang in 1989. Alcaraz is also the youngest to beat a top-three player at any major since the ATP computerized rankings began in 1973.