Naomi Osaka beats Dominika Cibulkova at Pan Pacific Open

Japan's Naomi Osaka beat Dominika Cibulkova 6-2 6-1 to reach the Pan Pacific Open quarter-finals on Wednesday in her first match since her US Open triumph.

The 20-year-old, who stunned Serena Williams to become Japan's first grand slam singles champion earlier this month, fired down 10 aces on her way to victory in just 59 minutes.

Osaka came out firing with an impressive forehand down the line on the first point. The Slovakian had no answer to her opponent's firepower as the world No 7 wrapped up a comfortable victory with a ferocious cross-court backhand.

"I didn't really feel any pressure," said Osaka, who reached the Tokyo final in 2016.

"It was really difficult because she's such a great player but I just thought it was more fun.

"My serve was really good. I'm just grateful to be able to play here again."

Osaka will face the winner of the game between Estonia's Anett Kontaveit and Czech Barbora Strycova in the quarter-finals