What a week for the 20 year old taking down the world number 1️⃣, 2️⃣ &amp; 🥇 to win her first WTA Finals def 🇨🇳 Qinwen Zheng 3-6, 6-4, 7-6 (2) ⏰ 3:04 in Riyadh 🇸🇦 

13-2 to finish the season after splitting with Brad Gilbert post US Open. 

#TheFirstServe