Ashleigh Barty beat defending champion Elina Svitolina to win the WTA Finals title and bring to an end a brilliant year.

The 23-year-old, who won the French Open, beat Svitolina 6-4 6-3 to hand the Ukrainian her first defeat at the WTA Finals in 11 matches.

Barty, who is also the year-end world No 1, is the first Australian since Evonne Goolagong Cawley in 1976 to win the WTA Finals and only the fifth player to win this event on her debut appearance.

Barty's year could become even better as she will be a part of the Fed Cup final next week for Australia.

Both women started the final strongly, each losing only three points in their opening three service games and Barty in fact did not lose a point on her second serve in her first four service games.

The confidence the Australian had on her serve was starting to translate into her return game as she began to attack more often, particularly on Svitolina’s second serve.

Svitolina held firm until the tenth game of the set but the Ukrainian fell prey to a ripping forehand down the line from Barty and was a set down for just the second time this week.

The backhand slice is a trademark of Barty’s game, but a series of errors from that shot handed Svitolina the break to lead 2-1 in the second set. However the world’s best player broke straight back by hitting the line with brilliant winners time and again.

Svitolina fought back as she looked to extend the match and keep her chances of defending the title alive, but Barty continued to stay patient and force her opponent to make errors to get a chance to serve for the crown.

She served resiliently to get the job done to win her fourth title of the year and cap off a sensational season.