PHOENIX, Ariz. - Joey Votto took over the National League lead in home runs and gave rookie Luis Castillo all the support he needed to notch his first major-league win Saturday night.
Votto hit No. 26 - a two-run shot - in the first inning and Castillo (1-1) pitched 6 2-3 shutout innings in the Reds' 7-0 victory over the Diamondbacks.
Votto, who drove in three runs, is on pace to smash his personal best HR total of 37 in 2010. He had 29 in 2015 and 2016.
Scooter Gennett and Tucker Barnhart also homered for the Reds.
Castillo allowed three hits and a walk while striking out eight. It was his longest outing of the season.
Castillo, in his fourth career start, held the Diamondbacks hitless for the first three innings before giving up a single to Paul Goldschmidt. Castillo then retired the next nine batters.
The Diamondbacks managed only the three hits and lost their fourth game in the past five.
The Reds took control quickly, their first three batters of the game against Diamondbacks starter Taijuan Walker coming around to score.
Billy Hamilton started with a walk, stole second and scored on Zack Cozart's triple. Votto's homer made it 3-0.
Hamilton's two-out single in the fourth drove in Barnhart for a 4-0 lead, and Gennett's home run, a line drive over the right-field fence in the fifth, making it 5-0.
Gennett established a career high with his 15th homer of the season,and moved his hitting streak to seven games.
Walker (6-4) was done after five innings, allowing five runs and five hits with four strikeouts and three walks.
Castillo allowed two hits in the bottom of the seventh, the closest Arizona came to scoring. Wandy Peralta came on to get the final out of the inning.
Barnhart's second home run of the season came in the ninth off the Diamondbacks' Jorge De La Rosa.
Hamilton took over the major league lead in stolen bases with his second of the night Saturday, in the second inning. He finished with three for the game — all in the first four innings — and raised his total to 37.
The Diamondbacks held their annual alumni game before Saturday's game, with the red-jerseyed Diamondbacks defeating the team clad in throwback purple 3-0.
The Red Diamondbacks featured 1999 All-Star Matt Williams. The Purple Diamondbacks were led by former stars Luis Gonzalez, Mark Grace and Steve Finley.
Diamondbacks: OF Yasmany Tomas is still dealing with issues related to his strained right groin, and the injury has worsened. It could be some time before he is cleared for baseball activities. ... Ex-Red RHP J.J. Hoover (right shoulder) threw in a simulated game Saturday at the team's Salt River Fields at Talking Stick facility.
Reds: RHP Homer Bailey (1-2) brings a 12.66 ERA over his first three starts of the season into Sunday against Arizona. He's 2-2 in his career against the Diamondbacks.
Diamondbacks: LHP Patrick Corbin (6-8) is 1-1 with a 3.48 career ERA in six games against the Reds.