The Reds have won each of the first two games in their three-game set against the Red Sox after holding on for a 5-4 victory at Fenway Park.
Luke Weaver started the game for Cincinnati and struck out five batters while allowing three runs over five and two-thirds innings.
Ian Gibaut was credited with the win after pitching a scoreless inning of relief. Buck Farmer secured his first save of the season after striking out one in a scoreless ninth inning.
Spencer Steer led the way at the plate after hitting a two-run homer.
The Reds are now third in the NL Central at 26-and-29.
Josh Winckowski was charged with the loss after allowing three unearned runs over an inning and a third of relief.
Masataka Yoshida and Enmanuel Valdez each went deep in the loss for Boston, which is last in the AL East at 28-and-27.
(Photo by Maddie Meyer/Getty Images)