Anastasia Pavlyuchenkova will meet a familiar foe in the form of Kiki Bertens after comfortably dispatching of Dayana Yastremska 6-3 6-1 in round one of the Pan Pacific Open in Osaka.

World number 28 Yastremska – ranked 13 places higher than her opponent – showed flashes of her ability and power, but she ultimately paid the price for an erratic performance.

Yastremska made 23 unforced errors and could only hit 10 winners in the 55-minute contest, with Pavlyuchenkova's more considered and careful approach paying dividends.

Pavlyuchenkova's dubious reward is a fourth encounter of the year with Bertens, who she lost to at the US Open.

The Russian did come out on top at the Australian Open but was defeated by Bertens in St Petersburg prior to her loss at Flushing Meadows.

Ninth seed Elise Mertens – the highest ranked player in action on Monday – sailed through in similarly comfortable fashion, beating Whitney Osuigwe 6-3 6-1.

Alison Riske had no such fortune, however, losing to fellow American Nicole Gibbs 6-4 6-3 despite the latter being ranked 105 places below her in the WTA rankings.

Reigning Olympic champion Monica Puig crashed out in comprehensive fashion, as Zarina Diyas hammered her 6-0 6-3.

The day's longest contest – by far – lasted two hours and 43 minutes, as Viktoriya Tomova came through 4-6 6-3 6-2 against France's Alize Cornet.

Camila Giorgi was pushed all the way in the first set against Han Xinyun before easing to victory in the second, with her 7-6 (8-6) 6-1 triumph ensuring she was one of few to prevent a surprise.

Naomi Osaka is the top seed for the tournament, though she does not begin her bid for success on home soil until later in the week.

Madison Keys – the fifth seed – starts her campaign on Tuesday, as she goes up against Daria Kasatkina.