Pliskova's twin powers through in Tokyo

Tokyo - Fourth seed Kristyna Pliskova, twin sister of world number one Karolina, fired down 14 aces to see off Taiwan's Chang Kai-chen in straight sets Monday in the Japan Women's Open.

The Czech, a wildcard entry to the $250 000 Tokyo tournament, came through her first-round match 7-5, 7-5 despite a sluggish start in humid conditions. 

"My serve helped me today," said Pliskova, who holds the record for the most aces in a match on the women's WTA Tour with 31. 

"It's always tough after a Grand Slam - you don't know how you will feel," added the 25-year-old world number 41. 

It was her first match since being edged out 7-6, 7-6 in the second round of the US Open in New York to Slovakia's Magdalena Rybarikova. 

Pliskova next faces either Japan's Nao Hibino or a qualifier for a place in the quarter-finals of the hard-court event. 

Third seed Elise Mertens progressed with little fuss, the Belgian beating Russian Evgeniya Rodina 7-6, 6-1 while China's Wang Qiang saw off Taiwan's Hsieh Su-wei 7-5, 6-2. 

Much of the focus Tuesday will switch to Japan's Kimiko Date, playing in her final tournament just short of her 47th birthday. 

The former world number four faces Serbian Aleksandra Krunic, at 24 comfortably young enough to be her daughter.