They were the two standout players on the WTA Tour last season, featuring in three of the four Grand Slam finals between them, leading the rankings, and amassing more match wins than anyone else.
Now as Iga Swiatek and Ons Jabeur prepare to get their campaigns at Indian Wells under way on Friday, both will be aiming to overcome recent setbacks, albeit from very different stages of their seasons.
Swiatek last year established herself as the undisputed dominant force of women's tennis, winning eight titles - including Roland Garros and the US Open - and topping the world rankings with more than double the points of second-ranked Jabeur.
Perhaps the Pole set the bar too high, because the start to this season has been comparatively mixed. A surprise fourth-round defeat at the Australian Open, even if it was to eventual finalist Elena Rybakina, was followed by a rampant march to the Qatar Open title, clinched for the loss of just five games.