Australian Open: Third seed Muguruza labours past French wildcard Jessika Ponchet

The world number three took an hour and 24 minutes to quell the virtually unknown 21-year-old French world number 256.

Spain's Garbine Muguruza makes a forehand return to France's Jessika Ponchet during their first round match at the Australian Open | AP

MELBOURNE: Garbine Muguruza wore heavy strapping on her injured right thigh as she laboured to a 6-4, 6-3 victory against wildcard Jessika Ponchet in the Australian Open first round on Tuesday.

The world number three took an hour and 24 minutes to quell the virtually unknown 21-year-old French world number 256.

Muguruza said before her match she was hoping to be "pain-free" to begin her Australian Open campaign, but her mobility was hampered and she looked anything but fully fit against Ponchet.

A quarter-finalist in Melbourne last year, Spain's Muguruza dropped her first service game but from there battled back to take the first set in 43 minutes.

"It wasn't easy. I didn't know anything about her," said Muguruza of her opponent who was making her first main draw appearance in a WTA event, let alone a Grand Slam.

"She's super talented. Serves and volleys, so I had to stay very concentrated."

The Wimbledon champion had a problematic start to the year, pulling out of the Sydney International to protect her right thigh.

Only a week earlier she had retired from the Brisbane International with severe cramps.

Her bad luck almost continued when she clutched her left knee as her shoe stuck awkwardly in the court at 2-2, 30-30 in the second set, bringing gasps from the Margaret Court Arena crowd.

But she recovered to outlast Ponchet in a game that went to a marathon six deuces and take a break of serve and then broke again to seal the win.

Muguruza, seeded three, next faces Taiwan's Hsieh Su-wei who prevailed in a see-saw match against China's Zhu Lin 0-6, 6-0, 8-6.

The two-time Grand Slam winner is in the same half of the draw as world number one Simona Halep and is projected to face another Frenchwoman, number eight seed Caroline Garcia, in the quarters.