Latos (10-3) won this third straight start, scattering four hits while walking three and striking out five.
Jonathan Broxton got the final two outs of the eighth inning and Aroldis Chapman completed the whitewash with his 24th save for the National League Central leaders, who improved their advantage over second-place Pittsburgh to 4 1/2 games.
Latos' shot in the fifth inning gave the Reds a three-run lead after Chris Heisey's inside-the-park homer in the second had broken a scoreless tie.
Cincinnati claimed its fourth straight win and its 14th in 15 games.
Wandy Rodriguez (7-10) absorbed the loss, surrendering three runs on seven hits over seven frames.