In her last Grand Slam quarterfinal, the Spaniard fell apart in New York. She took the lessons to Gauff in Melbourne, and won.

Aryna Sabelenka remains on course for a historic third straight Australian Open title after beating No. 11 seed and close friend Paula Badosa 6-4 6-2 in Thursday’s first semifinal.

Coco Gauff lost to Spain’s Paula Badosa on Tuesday in the Australian Open. After back problems that saw her fall in the rankings from No. 2 to No. 140, the Spanish player’s determination halted Gauff’s hot streak.