Melbourne - Big-hitting Spaniard Garbine Muguruza struggled with injury as she battled into the Australian Open second round Monday with a straight-sets win over New Zealand's Marina Erakovic.
The French Open champion, seeded seven, needed a medical time-out after the first set for what appeared to be a foot problem before returning to win 7-5, 6-4 on Margaret Court Arena.
"It was very tough when you're playing and starting to feel pain," she said afterwards.
"I tried to just stay calm and fight for the match. It's always tough against Marina and I'm very happy because it's the first major of the year and you're always a bit nervous."
Muguruza announced her arrival as a major force with her shock straight-sets victory over Serena Williams in last year's Roland Garros final, but consistency has been elusive.
She is yet to go beyond the fourth round at Melbourne Park but said ahead of the tournament she was learning to manage the pressure, and she had a good workout against Erakovic, ranked 110th.
Muguruza used her powerful groundstrokes to grind down the Kiwi as they exchanged service breaks in the opening set before the Spaniard took charge and broke again in the 11th game.
The 23-year-old, who opened her season with a run to the Brisbane International semi-finals before retiring with a right thigh injury, was broken early in the second set before knuckling down to romp to victory.
She will next play American Samantha Crawford, who beat compatriot Lauren Davis 4-6, 6-3, 6-0.
Results from the Australian Open on Monday:
Men's singles
1st round
Jeremy Chardy (FRA) bt Nicolas Almagro (ESP) 4-0 ret
Ryan Harrison (USA) bt Nicolas Mahut (FRA) 6-3, 6-4, 6-2
Tomas Berdych (CZE x10) bt Luca Vanni (ITA) 6-1 ret
Viktor Troicki (SRB x29) bt Damir Dzumhur (BIH) 6-4, 6-4, 2-6, 2-6, 6-3
Alex De Minaur (AUS) bt Gerald Melzer (AUT) 5-7, 6-3, 2-6, 7-6 (7/2), 6-1
Sam Querrey (USA x31) bt Quentin Halys (FRA) 6-7 (10/12), 7-6 (7/4), 6-3, 6-4
Mischa Zverev (GER) bt Guillermo Garcia-Lopez (ESP) 6-3, 7-6 (7/5), 6-4
Kei Nishikori (JPN x5) bt Andrey Kuznetsov (RUS) 5-7, 6-1, 6-4, 6-7 (6/8), 6-2
Bernard Tomic (AUS x27) bt Thomaz Belluci (BRA) 6-2, 6-1, 6-4
Victor Estrella (DOM) bt Aljaz Bedene (GBR) 7-6 (9/7), 7-5, 0-6, 6-3
Sam Querrey (USA x31) bt Quentin Halys (FRA) 6-7 (10/12), 7-6 (7/4), 6-3, 6-4
Women's singles
1st round
Irina Begu (ROM x27) bt Yaroslava Shvedova (KAZ) 5-7, 6-3, 6-4
Samantha Crawford (USA) bt Lauren Davis (USA) 4-6, 6-3, 6-0
Garbine Muguruza (ESP x7) bt Marina Erakovic (NZL) 7-5, 6-4
Shelby Rogers (USA) bt Simona Halep (ROM x4) 6-3, 6-1
Mona Barthel (GER) bt Destanee Aiava (AUS) 6-3, 7-6 (7/4)
Monica Puig (PUR x29) bt Patricia Tig (ROM) 6-0, 6-1
Varvara Lepchenko (USA) bt Kiki Bertens (NED x19) 7-5, 7-6 (7/5)
Duan Yingying (CHN) bt Rebecca Sramkova (SVK) 6-3, 6-4
Julia Goerges (GER) bt Katerina Siniakova (CZE) 3-6, 6-3, 6-4
Jelena Jankovic (SRB) bt Laura Siegemund (GER x26) 6-1, 1-6, 6-4
Alison Riske (USA) bt Madison Brengle (USA) 7-5, 6-3
Kristyna Pliskova (CZE) bt Viktorija Golubic (SUI) 6-3, 2-6, 6-4
Sorana Cirstea (ROM) bt Irina Khromacheva (RUS) 6-2, 6-1
Anastasija Sevastova (LAT x32) bt Nao Hibino (JPN) 6-4 ret
Kristina Kucova (SVK) bt Christina McHale (USA) 6-4, 6-0
Venus Williams (USA x13) bt Kateryna Kozlova (UKR) 7-6 (7/5), 7-5
Natalia Vikhlyantseva (RUS) bt Vania King (USA) 6-3, 6-2
Jaimee Fourlis (AUS) bt Anna Tatishvili (USA) 6-4, 6-3
Zhang Shuai (CHN x20) bt Aliaksandra Sasnovich (BLR) 6-0, 6-3
Pauline Parmentier (FRA) bt Misaki Doi (JPN) 7-5, 7-5