Top 5 Photos, 11/16: 'Playing for' injured Berrettini, alternate Jannik Sinner wins ATP Finals debut in Turin

How it started for Garbiñe Muguruza going into the semifinals of the WTA Finals...

How it ended... a 6-3, 6-3 winner over countrywoman Paula Badosa. Muguruza is a win away from becoming the first Spaniard to triumph at the year-end championships.

Stepping in as an ATP Finals alternate for injured compatriot Matteo Berrettini, Italian Jannik Sinner wowed his home crowd by dismissing Hubert Hurkacz, 6-2, 6-2. "I am going to play for (Matteo) at this tournament because he deserves to be here," Sinner said.

Sinner has given himself a shot at reaching the semifinals on his debut. A win over world No. 2 Daniil Medvedev would seal it, or if Hurkacz defeats Alexander Zverev.

Defending champion Medvedev posted his seventh successive win at the season finale, holding off Zverev, 6-3, 6-7 (3), 7-6 (6).