Mumbai, Sept. 3 -- Coco Gauff walked back to the baseline, shoulders drooped, face wrinkled in agony. "Nothing's working," she mouthed to her player's box. At the other end of the court, Naomi Osaka took a few shadow swings, a bright smile on her face. The stark contrast in their body language told the story of their fourth round US Open match. The first time they met was at the 2019 US Open. Osaka was the defending champion and Gauff a 15-year-old destined for big things. Osaka won, but in a ground-breaking gesture, she asked her young opponent to stay behind and address the crowd rather than walk off alone through the tunnel. On Monday night, as Osaka handed Gauff a 6-3, 6-2 defeat, there was no stopping the 21-year-old American, who pack...