Rookie Matt McLain launches first career grand slam as Reds beat Diamondbacks 9-6

The Diamondbacks began the day two games behind the first-place Dodgers in the NL West, and the second-place Reds trail the Brewers by 1 1/2 games in the NL Central.

McLain’s slam came on an 0-2 fastball from right-hander Justin Martinez.

“It was a huge hit in the game,” Reds manager David Bell said. “The most impressive thing (is) to be able to hit a fastball like that, when you’re down in the count. To hit a special fastball like that and have that kind of power to be able to drive the ball to the opposite field says a lot right there.”

Ketel Marte had his sixth career multi-hit game, homering twice with a triple, and Alek Thomas added a homer for Arizona.

“We were inefficient in a lot of different areas,” Diamondbacks manager Torey Luvollo said. “Ton of things happened today. Straight fastballs to fastball hitters, one ends up getting clipped for a grand slam.”

Alex Young (4-0) worked a third of an inning and picked up the victory. Alex Diaz recorded his 28th save.

Marte opened the scoring in the first inning with a 351-foot shot to right field. The Reds countered in the bottom of the inning as Nick Sensel scored on a Spencer Steer’s groundout to third.

The Diamondbacks thought they had turned an inning-ending double play in the second. But, replay overturned the ruling that Senzel was out at first and Tyler Stephenson scored to give the Reds a 2-1 lead.

Thomas doubled and scored on Geraldo Perdomo’s single to tie the score at 2 in the third.

After a pair of walks in the bottom of the fourth, Steer, who leads NL rookies in RBIs and drove in three runs Friday, smacked a two-run double to give the Reds a 4-2 lead.

Tommy Henry (5-3) took the loss. The 25-year-old left-hander allowed four walks — three of which scored — four hits and stuck out two in 4 1/3 innings.

“I just shot myself in the foot with those walks,” Henry said. “I thought I was a little bit too fine at times. That bit us. I need to attack the middle.”

In the fifth inning, Marte tripled off Will Benson’s glove in right, scoring Perdomo with the Diamondbacks’ third run.

Benson atoned for his misplay with an RBI double in the bottom of the inning.

Three batters later, McLain launched Martinez’s pitch 366 feet to the opposite field for a grand slam and a 9-3 lead. The 23-year-old shortstop has nine homers in 56 games.

“He blew two past me,” McLain said. “I made a little adjustment after the first one to start earlier. Power comes with knowing the pitches that I can hit best and looking for that pitch.”

Luvollo said controlling the Reds’ running game will be key in the series. The Diamondbacks didn’t get off to a good start on Friday when the Reds’ pulled off a double steal in the first, leading to a run.

“That was a frustrating run in the first inning, because that’s my fault,” Henry said. “I was trying to focus on the hitter with no looks, and they took advantage of that.”

The Reds lead the major leagues with 117 stolen bases.

Diamondbacks: LHP Andrew Chafin was reinstated from the paternity list and LHP Joe Mantiply was optioned to Triple-A Reno. Chafin and his wife Shelbi welcomed their third child, Bobby, on July 19.

Reds: RHP Tejay Antone (Tommy John surgery) will begin a minor league rehab assignment on July 25. … RHP Luke Weaver is expected to make his next start after being struck on the left arm with a line drive.

LHP Brandon Williamson (1-2, 4.96), who twice has picked runners off second base, will look to slow the D-backs, one of three teams with 100 or more stolen bases. RHP Brandon Pfaadt (0-3, 9.82) will be recalled from Triple-A Reno to start for Arizona.

AP MLB: https://apnews.com/hub/mlb and https://twitter.com/AP_Sports