On Coco Gauff’s only set point during the final of the Miami Open on Saturday afternoon, she raced to the far corner where Aryna Sabalenka painted both lines and somehow ripped it crosscourt on the sideline to force a weak forehand reply from the world No. 1 Belarusian. Most of the sold-out, 16,830 pro-Coco fans in Hard Rock Stadium erupted in applause for their hometown favorite, partly because they craved a third set of this sky-high level confrontation. After all, Gauff, the fourth seed, won her first four matches this tournament in three sets, a place the dominant Sabalenka rarely goes to.