Ana Ivanovic is into just her third Grand Slam quarter-final since winning the French Open in 2008 after beating Ekaterina Makarova 7-5 3-6 6-1 in the fourth round of this year's tournament.
The Serb had to overcome a lengthy rain delay during the first set, as well as the ninth seed Russian.
The 27-year-old former world number one will face 19th seed Ukrainian Elina Svitolina, 20, in the next round.
Roger Federer plays Gael Monfils in the highlight of Sunday's schedule.