Emma Raducanu has dominated her first career matchup against Naomi Osaka, winning the showdown at the D WASHINGTON — Emma Raducanu dominated her first career matchup against Naomi Osaka , winning the showdown at the D.

Emma Raducanu handed No. 7 seed Marta Kostyuk a sixth consecutive loss Tuesday, defeating her 7-6 (4), 6-4 at the DC Open to prolong a slide that now has lasted more than two months. This was the fifth tournament in a row where Kostyuk exited in the first round;