The defending World Series champions have won eight of 10. They are 11 games over .500 for the first time this season and have their biggest lead in the NL Central, 3 1/2 games ahead of Milwaukee.
Left-hander Mike Montgomery (4-6) allowed four hits in six shutout innings, filling in for Jon Lester in the rotation. Joey Votto, Eugenio Suarez and Scott Schebler homered in the ninth for the Reds.
