Stefanos Tsitsipas was only able to create one break point opportunity in his win against John Isner.
Aryna Sabalenka is the only seeded competitor remaining in the Western & Southern Open as the field is down to four.
The defending Flushing Meadows champion showed glimpses of her best tennis in Cincinnati as she knocked out Serena Williams and Victoria Azarenka before losing 7-5 6-4 to American Jessica Pegula. Raducanu felt herself playing with some of the same freedom she displayed at last year's US Open, and she told reporters: "I think this week was a great step for me. "In the past year I think it's probably the first tournament or one of the few tournaments that I have actually started going for my shots more. Pegula is the top-ranked American, sitting five places above Raducanu at eighth in the world, and she was ultimately too consistent for the British player.