CINCINNATI - Diamondbacks first baseman Paul Goldschmidt wasn't sure how many RBI he had coming into Tuesday night's game.
"I knew I was somewhere in the 90s," he said.
He actually had 96. But, with one swing of the bat in the eighth inning, He reached the century mark. Goldschmidt hit his third career grand slam, and left-hander Patrick Corbin pitched his second career complete game, lifting Arizona to a 5-2 victory over the Cincinnati Reds on Tuesday night at Great American Ball Park.
"I knew when they were saying ‘Congrats on 100,'" said Goldschmidt, who now leads the National League in RBI and ranks third in the majors. "Like I've been saying, I worry about what I can control, not driving in runs. It was just nice to give Patrick some runs there."
Martin Prado added his 12th home run of the season for Arizona in the fourth inning.
Left fielder Chris Heisey hit a two-run homer off Corbin in the eighth, but Cincinnati could get no closer.
The Reds' loss, which reduced their lead over Arizona for the National League's second wild card spot to five games, was further magnified by an injury to Tony Cingrani, Tuesday night's starter.
Cingrani (6-3) left the game in the fourth inning with a strained lower back. He had filled a void in the rotation left by Johnny Cueto, who is on the disabled list for the third time this season.
"He said it's been bothering him on and off for the last couple of weeks," said Reds manager Dusty Baker of Cingrani. "He didn't tell me. These young guys want to stay in the big leagues and stay in the rotation. We'll have to wait and see how he's doing in the morning."
Corbin (13-3) was dominant, allowing two runs and six hits with no walks and 10 strikeouts. He threw 103 pitches, 73 for strikes. "If you look at the numbers, it was his most dominating performance," said D-backs manager Kirk Gibson.
Corbin cruised through seven innings, allowing no runs on just four hits.
"He's been impressive all year," said D-backs catcher Wil Nieves. "Today he was exceptional. And, to do it against a team like (Cincinnati) was impressive. His slider was really good against them."
The only blemish for Corbin was Heisey's home run in the eighth. But, with the D-backs leading 5-0, Corbin said he was just trying to get ahead. "I wanted to throw strikes in that situation," he said. "I was able to come back and finish the ballgame. We needed a win today. I just wanted to keep us in the game."
The Reds' bullpen, which hadn't allowed a run in eight of nine previous appearances, held Arizona hitless through three innings following Cingrani's exit.
But, the D-backs loaded the bases with one out in the eighth. And, Goldschmidt lined a 3-2 pitch from J.J. Hoover into the left-field seats for his 31st home run of the season.
"I just wanted to put something in play, get one run there to give us some breathing room," Goldschmidt said. "He threw a fastball and I was able to get it up in the air and get it out of there."
Hoover hadn't allowed a run in 26 1/3 innings, the longest active scoreless streak in the major leagues. "Yeah, I left it up in the zone," Hoover said. "I've faced Goldy a bunch of times in the minors, and you can't leave a pitch up like that (to him). If it's down, who knows what happens."
Cingrani, facing the Diamondbacks for the first time, retired the first 10 batters he faced before Prado launched a 1-1 pitch into the left-center-field stands, putting Arizona ahead 1-0. Two batters later, Cingrani's day was done.
"It finally bothered me enough that it was noticeable," Cingrani said. "I felt it before. It came on gradually. It hasn't been this bad. I could've (remained in the game), but they didn't want me to. I'll be pitching my next time. It's not bad."
NOTES: Goldschmidt's 100 RBI ties Adam LaRoche (2010) for the club record by a first baseman. ... Diamondbacks 2B Aaron Hill's double in the fourth inning extended his hitting streak to 13 games. ... Arizona C Miguel Montero took another step toward returning when he caught five innings on Monday night and went 1-for-3 with a double and an RBI in the rookie-level Arizona League. He is expected to catch again Wednesday. ... Reds LHP Sean Marshall felt good after throwing from 60 feet on Monday night. Marshall, on the DL with left shoulder tendinitis, will throw again Wednesday. ... RHP Bronson Arroyo is the first Reds pitcher since 1900 to produce six or more strikeouts without issuing a walk in three consecutive starts. Arroyo also has gone 22 2/3 straight innings without walking a batter. ... Entering Tuesday, Reds starting pitchers were 10-3 with a 2.08 ERA in the past 13 games.