Barty completed a 6-4 6-2 triumph in an hour and 15 minutes, but was not overly enamoured with a performance featuring 23 winners and seven aces.

"It was solid without being fantastic," the Australian said afterwards. "It was what we needed to do. 

"There were times where it was pretty good and there were times where it was challenging. Pretty happy with how we were able to get on a roll in the second set a little bit there."

Barty came from a set down to defeat Putintseva in Madrid this year but there were no such heroics required of the French Open champion this time around.

Next up, she faces Saisai Zheng, who thrilled the home crowd and stunned 13th seed Sloane Stephens with a 6-3 6-1 victory.

Naomi Osaka continued her dominant recent form as she dispatched Andrea Petkovic 6-2 6-0 inside an hour.

Fresh from victory on home soil at the Pan Pacific Open, Japan's reigning Australian Open champion hit 21 winners to 11 unforced errors en route to a sixth successive win and claimed a phenomenal 91 per cent of points on her first serve.

Defending Caroline Wozniacki was in a similarly uncompromising mood as she saw off Christina McHale 6-4 6-0.

Wozniacki flew out of the blocks, winning five of the first seven games, only for McHale to check her progress by converting a fourth break point of the opener.

The former world number one responded emphatically, however, and McHale did not win another game.

Petra Kvitova will face fellow seed and Venus Williams' conqueror Belinda Bencic after continuing her relentless record against Kristina Mladenovic.

Kvitova prevailed 6-4 6-4, taking her overall record against Mladenovic to 9-1, including three straight-sets victories this year.

"Against Kiki, I always have to play well because she can really play well, and she showed it in this match," Kvitova said. "I'm glad that I served pretty well and that it was a big weapon." 

Despite the punishing losses for McHale and Stephens, 15th seed Sofia Kenin and Alison Riske claimed some success for the United States contingent.

Riske was forced into a decider by Australia's Ajla Tomljanovic and came through 6-3 3-6 6-4.

Despite dropping serve with victory in sight at 5-3 in the third, Riske eventually saw off Tomljanovic in the next game – converting an eighth match point.

Kenin dropped her first two service games but regrouped to beat Anastasia Pavlyuchenkova 6-3 6-2 and faces third seed Elina Svitolina in round three.

Two seeds going no further are Angelique Kerber and last week's Wuhan winner Aryna Sabalenka, who went down in straight sets to Polona Hercog and Daria Kasatkina respectively.