Serena Williams' preparation for the Australian Open will begin with a testing match against fellow veteran Svetlana Kuznetsova in the first round at Auckland's ASB Classic.
Yet it's not the only clash of Grand Slam champions in the first week of the WTA season.
At the Brisbane International, three-time major winner Angelique Kerber will take on 2011 US Open champion Sam Stosur in the highest-profile of opening-round matches in a draw loaded with stars.
Top seed Williams is using the Auckland tournament, starting on Monday, to prepare for her shot at a record-equalling 24th Grand Slam singles crown in Melbourne.
Ranked world No.10, she was promoted to top seed when Canada's Bianca Andreescu - her conqueror in the US Open final last September - withdrew with a knee injury.
Williams hasn't played since, leaving an intriguing question mark over her ability to bag an eighth crown in Melbourne and move level with Margaret Court's all-time Grand Slam record.
It's more than a decade since Kuznetsova won the second of her grand slam titles, in Paris.
The 34-year-old has beaten Williams three times in their 13 meetings and she starts the year ranked 53rd after dipping outside the top 100 for a spell in 2019.
Williams is drawn in the same quarter as American 15-year-old phenomenon Coco Gauff, whose ranking has risen to 68th on the back of reaching the fourth round at Wimbledon six months ago.
Stosur has not beaten Kerber, an Australian Open champion in 2016, in four years; her last victory over the German came in Madrid in 2015.
Stosur won their first career meeting in semifinals of the 2011 US Open, yet Kerber has won their other six meetings to lead the head-to-head series.
“She’s obviously an extremely good player. She’s won Slams, she’s been at the top of the sport," Stosur said.
“So you know every time you’re going to play Angie, you’re going to have to work very hard, be willing to hang in some points, try and take charge.
“You want to play your game, but not be sucked into doing too much too early because you know she’s going to be able to run a lot of balls down and make some incredible winners.”