Top seed Sabalenka triumphed 7-5 6-2 to finish the year with a ninth straight win and back-to-back trophies following her success two weeks ago in Ostrava, where she was also victorious in the doubles alongside Mertens.

The Belarusian took an hour and 42 minutes to overcome the second seed, moving her level with Simona Halep for the most WTA Tour titles in 2020.

Mertens had a chance to serve out the opening set after breaking Sabalenka for the second time at 4-4, but she failed to do so and dropped her next service game as the match turned on its head.

Sabalenka made it three straight breaks early in the second and she somehow hung into a rally before producing a powerful backhand to secure another piece of silverware.

"Hopefully there's many more titles to come for our team … it's a tough period and I really appreciated having the opportunity to play here," said Sabalenka.

"Everyone, thank you so much. It's been an amazing week and I'm really happy to finish the season with a title."