Garbiñe Muguruza has added the WTA Finals to a résumé which includes two Grand Slam victories ©Getty Images

Garbiñe Muguruza is the Women's Tennis Association (WTA) Finals champion after defeating Anett Kontaveit in straight sets in Guadalajara.

The Spaniard broke Kontaveit's serve five times en route to a 6-3, 7-5 win.

Having lost her opening match of the group stage against Czech Karolína Plíšková, Muguruza reeled off four wins in a row to win the end-of-season finale in Mexico.

That included another straight-sets win against Estonia's Kontaveit.

After losing the first set in the final, Kontaveit went a break up in the second and appeared to be growing into the match, but Muguruza roared back.

With breaks in games 10 and 12, Muguruza won four games in a row to seal the match and the WTA Finals title.

Barbora Krejčíková, right, and Kateřina Siniaková also won an Olympic gold medal together this year ©Getty Images
Barbora Krejčíková, right, and Kateřina Siniaková also won an Olympic gold medal together this year ©Getty Images

"I'm just very happy I proved to myself once again I can be the best, I can be the maestra, like how we say in Spanish," Muguruza said after the win. 

"That puts me in a very good position for next year, a good ranking."

Muguruza is now up o world number three.

Czech duo Barbora Krejčíková and Kateřina Siniaková won the doubles crown, beating Elise Mertens from Belgium and Chinese Taipei's Hsieh Se-wei 6-3, 6-4.

Krejčíková had perhaps the best season in women's tennis, winning a maiden Grand Slam singles title at the French Open as well as doubles victories at Roland Garros and the Tokyo 2020 Olympics.