Williams struggled to find consistency in her fourth match of the season, giving up 12 unforced errors while making just 11 winners in Cincinnati.
Emma Raducanu earned a confidence-building win ahead of her US Open title defense as she swept past Serena Williams 6-4, 6-0 in Cincinnati.
Carlos Carrasco's prognosis after leaving his start against the Atlanta Braves will see him unavailable for up to a month.
Former Manchester United director Michael Knighton is in talks with several billionaires ahead of a potential takeover bid at Old Trafford.