London: Seven-time champion Roger Federer and 2013 winner Andy Murray look to reach the Wimbledon fourth round on Saturday.
Federer bids to extend his 18-match winning streak against Australian opponents at Grand Slams when he takes on big-serving Sam Groth in the opening match on Centre Court.
The 33-year-old Swiss beat Groth, the world number 69, in straight sets at last year`s US Open.
Groth is bidding to make the fourth round at a major for the first time and join compatriot Nick Kyrgios in the second week.
Murray, the third seed, has a 6-1 career lead over Italian veteran Andreas Seppi ahead of their showdown.
Seppi knocked Federer out of the Australian Open in January but his only win over the British star came back in 2006 in their first meeting.
The 31-year-old Seppi has reached the fourth round on four occasions -- at the 2012 French Open, 2013 Australian Open and Wimbledon and this year`s Australian Open.
Sixth seeded Czech Tomas Berdych faces Spain`s Pablo Andujar.
In the women`s draw, defending champion Petra Kvitova, who has only dropped three games, faces Serb 28th seed Jelena Jankovic.
Kvitova has a 4-2 lead over Jankovic but the two have never met at a Grand Slam.
Fifth seed Caroline Wozniacki faces Camila Giorgi trailing 2-1 in their career meetings.
Giorgi defeated the Dane at the 2013 US Open.
Wimbledon order of play on the show courts on Saturday, the sixth day of the 2015 tournament at the All England Club (x denotes seeding):
Centre Court (1200 GMT)
Samuel Groth (AUS) v Roger Federer (SUI x2)
Jelena Jankovic (SRB x28) v Petra Kvitova (CZE x2)
Andreas Seppi (ITA x25) v Andy Murray (GBR x3)
Court One (1200 GMT)
Caroline Wozniacki (DEN x5) v Camila Giorgi (ITA x31)
James Ward (GBR) v Vasek Pospisil (CAN)
Gael Monfils (FRA x18) v Gilles Simon (FRA x12)
Court 2 (1130 GMT)
Garbine Muguruza (ESP x20) v Angelique Kerber (GER x10)
Timea Bacsinszky (SUI x15) v Sabine Lisicki (GER x18)
Tomas Berdych (CZE x6) v Pablo Andujar (ESP)
Court 3 (1130 GMT)
Viktor Troicki (SRB x22) v Dustin Brown (GER)
Jo-Wilfried Tsonga (FRA x13) v Ivo Karlovic (CRO x23)
Court 12 (1130 GMT)
Nikoloz Basilashvili (GEO) v Roberto Bautista Agut (ESP x20)
Madison Keys (USA x21) v Tatjana Maria (GER)
Court 18 (1130 GMT)
Kristyna Pliskova (CZE) v Monica Niculescu (ROU)
Agnieszka Radwanska (POL x13) v Casey Dellacqua (AUS)
Magdalena Rybarikova (SVK) v Olga Govortsova (BLR)