Women's fourth round matches on Sunday at the Australian Open sees Angelique Kerber take on Flavia Pennetta, Serena Williams play Ana Ivanovic, Casey Dellacqua battle Eugenie Bouchard and Li Na face Ekaterina Makarova.
Meanwhile, men's Round 4 matches will pit Novak Djokovic against Fabio Fognini, Stanislas Wawrinka against Tommy Robredo, David Ferrer against Florian Mayer and Tomas Berdych and Kevin Anderson.
Action on Rod Laver Arena begins with a women's fourth round clash between German ninth-seed Kerber and Italian 28th-seed Pennetta.
Kerber has advanced to the Round of 16 by firstly beating Australia's Jarmila Gajdosova in three sets, and then beating Alla Kudryavtseva and Alison Riske both in two as she now looks to make a Grand Slam quarter-final for just the fourth time of her career.
While Pennetta is into the fourth round with comfortable straight-sets wins over Romania's Alexandra Cadantu, Portugal's Monica Puig and Germany's Mona Barthel to already equal her best ever performance in Melbourne.
Kerber and Pennetta have played four times previously with each winning twice with the most recent clash coming at the 2012 French Open where Kerber won in three sets.
The winner will take on the winner of the Li Na-Ekaterina Makarova match-up in the quarter finals.
Next up on Rod Laver Arena on Sunday is world No. 1 Serena Williams in action against former world No. 1 Ana Ivanovic.
Williams has been in scintillating form already this summer winning the Brisbane International and cruising through the first three rounds in Melbourne beating Ashleigh Barty, Vesna Dolonc and Daniela Hantuchova dropping just 12 games in the process
The 32-year-old is attempting to win for the first time in Melbourne since 2010, to win the Australian Open for the sixth time and her 18th Grand Slam overall.
Meanwhile, Ivanovic is currently seeded No. 14 and has advanced to the fourth round by beating Kiki Bertens, Annika Beck and Sam Stosur as she now attempts to win through to just her second Grand Slam quarter-final in her last 21 majors since winning the 2008 French Open.
Williams and Ivanovic have met just the four times previously with the American winning on each occasion with three of those coming at the US Open – in 2006, 2011 and 2012. Ivanovic is yet to even win a set against Williams.
The winner will take on the winner of the Casey Dellacqua-Eugenie Bouchard clash in the quarter finals.
The final match on Rod Laver Arena in the afternoon will be the first men's fourth round clash when world No. 2 and four-time Australian Open winner Novak Djokovic taking on Italian 15th-seed Fabio Fognini.
Djokovic has enjoyed a remarkable run at the Australian Open the last six years winning the title four times and losing in the quarter finals the other two.
This year, he has cruised through the first three rounds with comfortable straight-sets wins over Lukas Lacko, Leonardo Mayer and Denis Istomin.
Fognini is coming off a 2013 that saw the 26-year-old finish with a career-high ranking of 16.
And this week in Melbourne he has got through to the fourth round for the first time having never previously got beyond the second round at the Australian Open, and having only ever once before making a Round of 16 at any major – the quarter finals at the 2011 French Open.
Djokovic and Fognini have met five times previously of which the Serb has won all of them mostly recently last year in Shanghai.
Djokovic is yet to drop a set to those five matches against Fognini.
The winner will take on the winner of the night clash between Stanislas Wawrinka and Tommy Robredo.
The Rod Laver Arena night session begins with Australia's Dellacqua taking on emerging Canadian star Bouchard.
Dellacqua has enjoyed a tremendous run into the Australian Open fourth round by beating Vera Zvonareva, Kirsten Flipkens and Jie Zheng all in straight-sets in what is her best Grand Slam performance since also making the Round of 16 in Melbourne in 2008.
The West Australian 28-year-old is in the form of her career and now looking to make a quarter-final at a major for the first time.
Meanwhile, Bouchard is at the start of what is looming to be a tremendous career with the 19-year-old already seeded at No. 30 and having advanced to the fourth round by beating Hao Chen Tang, Virginie Razzano and Lauren Davis all in straight-sets.
Dellacqua and Bouchard have never previously met nor been into a Grand Slam quarter-final.
The night will conclude on Rod Laver Arena with what is sure to be a high quality and entertaining affair between eighth-seeded Swiss Stanislas Wawrinka and 17th-seeded Spaniard Tommy Robredo.
The pair are two of the best pure shot makers in the world, particularly on the backhand side, and the match will be a tennis purists' dream as the veteran pair desperately try to make the quarter finals.
Wawrinka has advanced to the fourth round by beating Andrey Golubev and Alejandro Falla while receiving a third round walkover thanks to Canada's Vasek Pospisil.
Robredo is in the form of his career continuing on his form from 2013 that finished with him beating Roger Federer on the way to the US Open quarter finals.
This week in Melbourne, he has beaten Lukas Rosol in five sets, Julien Benneteau in four and Richard Gasquet in four.
Wawrinka and Robredo have met seven times previously with the Spaniard having won six of those including twice in 2013 at the 2006 US Open. Wawrinka's only win came in 2007 at New Haven.
Fourth round women's singles action begins on Hisense Arena when two-time Australian Open runner-up and former French Open champion Li Na takes on Russia's 22nd-seed Ekaterina Makarova.
Li Na has enjoyed tremendous success in Melbourne having made two finals and a semi-final over the past four years.
This week the world No. 4 has won through to the fourth round by beating Ana Konjuh, Belinda Bencic and Lucie Safarova.
Russia's Makarova is into the fourth round for the fourth straight year in Melbourne and has got there this year by beating Venus Williams, Irina Falconi and Monica Niculescu.
Li Na and Makarova have met on the WTA Tour four times with the China world No. 4 winning all of them all including twice in a Grand Slam – at the 2008 and 2013 US Opens.
Next up is a men's fourth round match on Hisense Arena with unseeded German world No. 37 Florian Mayer taking on Spanish third-seed David Ferrer.
Mayer has enjoyed a terrific run so far in Melbourne making his first fourth round at the tournament and just the third overall in his career.
He has made the Round of 16 by beating Denis Kudla, Mikhail Youzhny and Jerzy Janowicz.
Ferrer has quietly gone about his business making the fourth round by beating Alejandro Gonzalez, Adrian Mannarino and Jeremy Chardy as the 31-year-old continues to try to win his first major title.
Ferrer and Mayer have met seven times on the ATP Tour with the Spaniard leading the German 4-3.
Two of those have been at a Grand Slam at the 2008 and 2011 US Opens with Ferrer winning both of those. However, Mayer won their only meeting in 2013 in straight-sets in Shanghai.
The winner will take on the winner of the battle of the big men Tomas Berdych and Kevin Anderson taking place on Margaret Court Arena.
Berdych has been threatening to win a Grand Slam for several years now with his best being a Wimbledon final and this week in Melbourne he is showing the form to suggest he could really make his mark after beating Aleksandr Nedovyesov, Kenny de Schepper and Damir Dzumhur all in straight-sets.
Meanwhile, South African 19th-seed Anderson has already had two five-setters in the first round against Czech Jiri Vesely and third round against France's Edouard Roger-Vasselin.
Berdych and Anderson have met nine times previously with the Czech world No. 7 winning all seven including the last two Australian Opens in the third and fourth rounds.