BRISBANE • Ukraine's Elina Svitolina believes she can finally win a Grand Slam title this year and also become world No. 1 despite a host of challengers for the coveted top ranking.

Svitolina, currently ranked sixth in the world, was speaking after an impressive 6-2, 6-4 win over Spain's Carla Suarez Navarro in the first round of the Brisbane International yesterday.

The 22-year-old cruised through the first set but was forced to fight harder in the second as Suarez Navarro began to find her range with powerful groundstrokes.

But the Spaniard faltered while serving at 4-5 and Svitolina was able to close out the match in just under 90 minutes.

"This match was a good example that I can play a good level of tennis, a high level of tennis," Svitolina said. "So I will try to continue to work and to, you know, to just be focused on these kind of things.

"That's what's important for me - and then the Grand Slam and No. 1 is all going to come if I have my game, if I'm healthy, if I'm playing my best."

She won five titles last year and rose to a career-high world No. 3 and qualified for the season-ending WTA Finals in Singapore.

She said she had worked hard - especially on her serve - during the off-season and that was mainly the reason why she felt positive that she can challenge for a Grand Slam title or take the top ranking.

Five women held the top spot at various times last year - Serena Williams, Angelique Kerber, Karolina Pliskova, Garbine Muguruza and current No. 1 Simona Halep.

Svitolina added that her ability to raise her game to see off someone as dangerous as world No. 40 Suarez Navarro showed she was also capable of taking the next step.

"I was expecting Carla to come back very strong in the second set," she said.

"She's been on top for many years and knows how to handle the pressure and intensity. I was just trying to play my best and bring my own intensity, giving 100 per cent."

Svitolina will take on Ana Konjuh in the second round following the Croat's 6-1, 6-2 win over Dutchwoman Kiki Bertens on Sunday.

In another first-round encounter, Britain's Johanna Konta was stretched before she defeated last year's US Open finalist Madison Keys of the United States 4-6, 6-4, 6-3 in just over two hours.

Twice Wimbledon champion Petra Kvitova, however, withdrew from Brisbane with a viral illness.

The 27-year-old Czech was unable to take to the court in her first-round match against Estonian Anett Kontaveit and was replaced in the draw by lucky loser Heather Watson.

"I'm really disappointed to withdraw from the Brisbane International," she was quoted as saying on the WTA website.

"Unfortunately I picked up a virus on the flight to Australia and I haven't been able to get healthy in time to play here. I'm sorry not to be in the draw."

Halep began the year in emphatic style with a 6-4, 6-1 victory over Nicole Gibbs, as Maria Sharapova also romped through her first-round match at the Shenzhen Open yesterday.

Romania's Halep, like Svitolina, will be seeking her maiden Grand Slam title at the Australian Open which starts on Jan 15.

Five-time Grand Slam champion Sharapova, meanwhile, dispatched Halep's compatriot world No. 59 Mihaela Buzarnescu 6-3, 6-0.

AGENCE FRANCE-PRESSE, REUTERS