Tag: Svetlana Kuznetsova
The triumph was the fourth in a row on hard courts for the 16th-seeded Keys over Kuznetsova and the 24-year-old's fifth career title.
Australia's Ashleigh Barty was off the boil against Russia's Svetlana Kuznetsova, who is back on form following several seasons of injuries including a wrist problem.
Ashleigh Barty is set to compete in the semi-finals while Naomi Osaka 's dream to win the Cincinnati Masters has been dashed with a knee injury.
The seven-time Cincinnati champion was unable to make an impression as he played only his second match since losing the Wimbledon final to Novak Djokovic.
The Russian has lost the opening match in each of her last three tournaments, including at Wimbledon and the French Open.
The 16th-seeded Williams came out strong in the first set, firing winners and attacking the net to put pressure on Russian, who won the tournament in 2004.