In the third round-robin match at the WTA Finals Elina defeated the top-seeded Simona Halep of Romania: 6-3, 6-4. In 1 hour and 10 minutes of the match Elina hit one ace to two double faults, converted three out of five breakpoints. It's her third victory in matches against Simona Halep this year. However, this victory did not allow Elina to continue her WTA Finals campaign as Caroline Garcia defeated Caroline Wozniacki earlier in the day, so the two took the semifinals spots from the Red Group. 

"It was not the best week for me. Today was my last match of the season, I just played very freely", Elina said after the match. "Today was a good match, I'm very, very happy that I finished with the win and now I'm leaving Singapore with the goods. I had an amazing year, my goal was always to finish the season at the WTA Finals. At the beginning it was not so good but then I started to win titles. For me it was a good signal that I'm on the right way. Yes, I'm very, very happy to play here. Now I leave Singapore in a good mood and that's all that matters". 

Elina finished her season with 53 wins to 14 losses (11-5 against top-10 players). She added five more trophies to her collection, winning in Taipei, Dubai, Rome, Istanbul and Toronto. In September Elina also set a new personal and national record as World No. 3 on the WTA list.