NEW YORK—Naomi Osaka overcame a slow start to beat Czech Marie Bouzkova 6–4 6–1 and get her U.S. Open title defense under way in front of a roaring capacity crowd at Flushing Meadows, New York, on Monday. Unseeded Bouzkova held her own through much of the first set but failed to convert on four break point opportunities against the Japanese four-time Grand Slam winner. Osaka, who fired 21 winners but committed 13 unforced errors in the first set, broke Bouzkova’s serve at 5–4 to win the opener and never looked back, winning the first five games of the second despite struggling with her first serve. The world number three closed out the match with a forehand winner, offering a smile and a wave to the stands that were empty a year ago. “I’m the type of player that wants to entertain a crowd as well. I think last year I …