Melbourne - Czech seventh seed Karolina Pliskova battled through to the Australian Open last 16 on Saturday with a tough three-set win over Italy's Camila Giorgi.
Pliskova downed the 27th seeded Italian 6-4, 3-6, 6-2 after a 131 minute arm wrestle to set up a fourth round meeting with Spanish 18th seed Garbine Muguruza.
Former world number one Pliskova took the first set at a canter and appeared to be cruising until Giorgi lifted in the second and forced a decider.
The Czech took a decisive break early in the final set after a marathon game that went for 13 minutes and went to deuce five times.
"I had trouble sometimes but I just stayed calm even though I lost the second set. I had my chances but that's tennis," she said.
"I was very positive in the third set and I'm very happy to be through."
She has made the quarter-finals in her last two appearances at Melbourne Park and entered this year's tournament on a high after winning the Brisbane International warm-up.
The 26-year-old has been a regular in the second week of Grand Slams in recent years, reaching the quarters or better six times since late 2016, but is still searching for a breakthrough win.
She has a 7-2 winning record over two-time Grand Slam champion Muguruza, including four straight sets victories on hard courts.
But even if she gets past the Spaniard she is in a tough section of the draw that pits her against either world number one Simona Halep or 23-time major winner Serena Williams in the last eight.
Collated results from Day 6 of the Australian Open on Saturday:
Daniil Medvedev (RUS x15) bt David Goffin (BEL x21) 6-2, 7-6 (7/3), 6-3
Kei Nishikori (JPN x8) bt Joao Sousa (POR) 7-6 (8/6), 6-1, 6-2
Pablo Carreno-Busta (ESP x23) bt Fabio Fognini (ITA x12) 6-2, 6-4, 2-6, 6-4
Milos Raonic (CAN x16) bt Pierre-Hugues Herbert (FRA) 6-4, 6-4, 7-6 (8/6)
Novak Djokovic (SRB x1) bt Denis Shapovalov (CAN x25) 6-3, 6-4, 4-6, 6-0
Alexander Zverev (GER x4) bt Alex Bolt (AUS) 6-3, 6-3, 6-2
Borna Coric (CRO x11) bt Filip Krajinovic (SRB) 2-6, 6-3, 6-4, 6-3
Lucas Pouille (FRA x28) bt Alexei Popyrin (AUS) 7-6 (7/3), 6-3, 6-7 (10/12), 4-6, 6-3
Naomi Osaka (JPN x4) bt Hsieh Su-wei (TPE x28) 5-7, 6-4, 6-1
Elina Svitolina (UKR x6) bt Shuai Zhang (CHN) 4-6, 6-4, 7-5
Anastasija Sevastova (LAT x13) bt Wang Qiang (CHN x21) 6-3, 6-3
Serena Williams (USA x16) bt Dayana Yastremska (UKR) 6-2, 6-1
Madison Keys (USA x17) bt Elise Mertens (BEL x12) 6-3, 6-2
Simona Halep (ROU x1) bt Venus Williams (USA) 6-2, 6-3
Garbine Muguruza (ESP x18) bt Timea Bacsinszky (SUI) 7-6 (7/5), 6-2
Karolina Pliskova (CZE x7) bt Camila Giorgi (ITA x27) 6-4, 3-6, 6-2