Denis Shapovalov held off a late charge 14th-seeded Kyle Edmund of Britain for a 6-4, 7-5 win in the second round of the Western and Southern Open in Cincinnati.
Earlier, Canadian Milos Raonic cruised past Dusan Lajovic at the U-S Open tuneup event. Raonic will play Malek Jaziri of Tunisia today.
Eighth-seeded Petra Kvitova dealt with former world number one Serena Williams in three sets in the second round of the Western and Southern Open.
Williams also was knocked out in her last tournament at San Jose two weeks ago after reaching the Wimbledon final.
Cincinnati was her fifth tournament since she had a baby last September.
She has dealt with blood clots and recently said she has been struggling with postpartum emotions.