SINGAPORE -- The 2018 BNP Paribas WTA Finals Singapore presented by SC Global opened on Sunday with a bang, as No.6 seed Elina Svitolina of Ukraine claimed only her second win in nine meetings with No.4 seed Petra Kvitova, beating the Czech, 6-3, 6-3, to take the lead in the round-robin portion of the event.

"I was playing good today, quite solid from the baseline and putting pressure on Petra today," said Svitolina, during the post-match press conference. "This was the most important thing and I think the key."

Live Blog: As it happened: Svitolina quells Kvitova in 2018 WTA Finals opening match

Svitolina had won their first meeting in Cincinnati in 2014, but since then, Kvitova had reeled off seven straight wins against the Ukrainian, going 14-1 in sets in the process. This year in Singapore, though, Svitolina completely turned that head-to-head on its ear, picking up the straight-set victory in 88 minutes behind four breaks of service out of nine opportunities.

"It's already very, very hard, each match," Svitolina stated, when asked about the gauntlet of the WTA Finals round-robin. "I already had the match today which was extremely hard for me, because I lost seven times against her. So, I mean, you couldn't ask for a harder start, I think."

"It's going to be a good match, the next match," the Ukrainian continued. "I will just try to recover and be ready for the next one, and I have to be ready for anything and just fight. Because it's round robin, so you don't know until the very end."

24-year-old Svitolina garnered her first Top 10 win since she defeated World No.1 Simona Halep in the Rome final. She takes the early lead in the White Group by emerging victorious in the inaugural match of the 2018 WTA Finals, as she seeks her first semifinal showing at the WTA Finals after going 1-2 in the round-robin portion of her debut appearance last year.

"Winning this match definitely gives me lots of confidence," Svitolina stated. "This win, definitely now I want to take as one to go forward."

Meanwhile, 2011 WTA Finals champion Kvitova opened the round-robin with a loss, in her first showing at the WTA Finals since the most recent of her five consecutive appearances in 2015. Kvitova fired 29 winners and an equal number of unforced errors, but could only muster up 42 percent of points on her second serve.

No.2 seed Caroline Wozniacki and No.7 seed Karolina Pliskova play later on Sunday to determine who else in the White Group will initially join Svitolina in the winner’s column.

Kvitova started shakily, dropping serve in the first game after a plethora of forehand errors. But deep returning helped her strike back immediately to level the set at 1-1, as she hoped to extend her streak of 12 consecutive sets won against Svitolina.

The Ukrainian, however, had other ideas, using spirited movement around the court to dismiss the sudden rash of dropshots from the Czech and stay even through 3-3. Svitolina then took advantage of more errors from Kvitova to reclaim her break lead at 4-3.

Kvitova ramped up her aggression even further, frequently rushing the net to try to grasp the break back, but Svitolina was unbowed. Svitolina opened up the 5-3 game with an amazing volley winner, and raced to triple set point. Kvitova double faulted on the second set point to hand Svitolina a set for the first time in their head-to-head since 2015.

Svitolina refused to give up the momentum as the second set started, showing her mettle by staving off three break points to hold for 2-1, and coming back from 0-30 down in her next service game, punching an ace to hold for 3-2.

The Ukrainian was rewarded for that fight with the decisive service break in the next game, as Kvitova’s forehand continued to misfire, giving Svitolina two break points. The sixth seed needed only one, as Kvitova sprayed another miscue long to provide Svitolina with a 4-2 advantage.

Kvitova survived a tough game at 4-3, holding with a lovely backhand volley and putting the pressure on Svitolina to serve out the match. But Svitolina was up to the task on the day, using incredible depth on her groundstrokes to come out on top during most rallies, and converting her first match point as a forehand by the Ukrainian forced a wide error from her opponent.