Singapore was first introduced to Elina Svitolina eight years ago at the inaugural Youth Olympic Games (YOG) here, in which the Ukrainian was the top seed and departed without a medal.

Now, they know her as the WTA Finals Singapore champion.

The 24-year-old claimed the biggest title of her career yesterday after beating American Sloane Stephens 3-6, 6-2, 6-2 to win the BNP Paribas WTA Finals Singapore presented by SC Global.

The 2hr 23min match was punctuated with entertaining long rallies that had both players running all over the court, the crowd at the Singapore Indoor Stadium gasping in delight and chair umpire Kader Nouni reminding spectators more than once to remain silent between points.

In a battle between two solid defenders, Stephens did not crumble, but Svitolina simply refused to yield.

She is undefeated in Singapore this year, and had beaten defending champion Caroline Wozniacki en route to winning the title.

Four of Svitolina's five matches here were three-setters, and yesterday's win means she has now won nine of nine finals in the past two years.

"The third set really showed that I was mentally just tough, that's what made the difference," said Svitolina, who will reach a career-high singles ranking of world No. 4 today.

"I had to stay very solid... I just told myself I'm not going to step back and (I'm) just going to fight for every ball, not going to give any opportunity to her and just be very, very tough.

"I think this is what willed me to do it today."

It is the first time she has beaten 2017 US Open champion Stephens on a hard court. The 25-year-old American dominated early, dictating the points well to win a first set in which Svitolina felt she "didn't have any answers".

With both trying to put pressure on each other, Svitolina was the steadier of the two in the second set as she out-rallied Stephens to force a decider.

She remained steady in the third and did not look back, falling to the ground in joy after Stephens hit a backhand wide.

Stephens, whose lone title this season came in Miami, was disappointed but proud of how her season has ended.

"I'm sad, but I know that if I keep doing what I'm doing and I keep working hard, there will be way more opportunities just like this one," she said.

"I can be happy with it not going my way today, but I did my absolute best and sometimes you just fall a little short. Obviously, going into 2019, I'll take a lot of confidence."

Said Svitolina, who now has four titles this year: "It was a very tough match but, in the end, I found a way here and there.

"One, two points made a difference in the second, and then we were in the third set already, and the fight began."

Wozniacki won her first Grand Slam title at the Australian Open this year after winning last year's season finale.

While Svitolina feels it is still too soon to say if yesterday's victory will lead to the same results, she added: "I cannot say that it was a perfect week... that I touched gold this week and everything was in.

"But I worked my way into the match, into the tournament and this really shows that I can play great tennis and (it's) definitely going to bring me lots of confidence."

She remembers being disappointed at finishing the Youth Olympic Games in Singapore without a medal.

This time, however, she will leave the Republic with a very valuable piece of silverware.