Wimbledon champion Petra Kvitova will hope to score early psychological points at the Hopman Cup as she seeks to send Denmark's Caroline Wozniacki crashing from the women's number one spot.
Czech Republic's Kvitova, currently ranked second but just 115 points behind the Dane, can put down an important marker when the two meet next week in singles action at the mixed-teams event in Perth, Western Australia.
Both players' form in the season-opener will also be under scrutiny before next month's Australian Open, where Wozniacki will again be under pressure to deliver her maiden Grand Slam title.
Kvitova, by contrast, is looking to extend her fairytale run of last season when she claimed six titles including Wimbledon and the WTA Championships, along with the Fed Cup as part of the Czech team.
Her victory at the season-ending Tour Championships in Turkey included a straight-sets win over Wozniacki, underlining her ascendancy with only her second win against the Dane.
Competition gets under way on Saturday and the women's top two will play when Denmark, represented by Wozniacki and 236th-ranked Frederik Nielsen, face the Czech Republic in Group A next Friday.
No rankings points are available at the Hopman Cup, featuring men's and women's singles and mixed doubles, but Kvitova and Wozniacki may meet again in the Sydney International in the week before the Australian Open.
Kvitova and team-mate Tomas Berdych are seeded top for the event, which appears wide open with defending champion Bethanie Mattek-Sands returning with new partner Mardy Fish, who replaces John Isner.
Chinese star Li Na will also look to start the season strongly as she bids to repeat January's run to the Australian Open final -- the prequel to her historic French Open win, which made her Asia's first Grand Slam champion.
Li, ranked fifth, and partner Wu Di will open the event on Saturday against the second-seeded French pairing of world number nine Marion Bartoli and Richard Gasquet, who lies 19th in the men's standings.
"I think we have a good team with two players who have had a very good year in 2011," Bartoli said. "It's a new beginning for every player so we will see how fit and ready to play everyone is.
"If we could win it would be a great start for the summer season leading up to the Australian Open. It's the first tournament of the year so you never know how you are going to go."
Other teams are host nation Australia, represented by Lleyton Hewitt and Jarmila Gajdosova, Spain's Fernando Verdasco and Anabel Medina Garrigues, and Bulgaria's Tsvetana Pironkova and Grigor Dimitrov.
America's Fish is no stranger to the Hopman Cup, having teamed with Serena Williams to win it in 2008.