CINCINNATI -- Jake Lamb didn't know about Arizona's late pitching change until an hour before the game. His two homers made it a moot point.
Lamb hit a pair of three-run homers , and Patrick Corbin pitched into the eighth inning during an emergency start on Thursday, leading the Diamondbacks to a 12-2 victory over the Cincinnati Reds.
Arizona stabilized itself by taking two of three in the series. The Diamondbacks had dropped eight of nine heading into the set, falling behind Colorado for the second NL wild-card spot.
"It seems like our offense is starting to heat up again, which is good," said Corbin, who pitched a season-high 7 1/3 innings.
Lamb homered in the first inning off Luis Castillo (1-3) and again in the ninth for a career-high six RBIs. Gregor Blanco and Ketel Marte added two-run shots as the Diamondbacks concluded a wacky series.
They won the opener 11-2 while getting outfielder J.D. Martinez in a trade with Detroit. A day later, Martinez got hit on the left hand by a pitch in his Diamondbacks debut and left with a bruise. He didn't play in the finale.
Scheduled starter Taijuan Walker was scratched after his wife, Heather, went into labor early Thursday morning. Corbin (7-9) was moved up a day and wound up with his first victory since June 16. The left-hander had gone 0-3 in his previous five starts.
Corbin got a phone call informing him of the switch just as he was about to fall asleep.
"It took me longer to fall asleep," he said. "It's a different feeling when you're pitching the next day."
Corbin gave up seven hits, including Eugenio Suarez's homer. The left-hander pitched out of a bases-loaded, no-outs threat in the fourth to hold the lead.
"I'm so proud of the guys fighting through very difficult circumstances in the last few games," manager Torey Lovullo said . "Nobody did better than Patrick Corbin."
Suarez homered again off J.J. Hoover in the eighth. Cincinnati fell to 1-6 since the All-Star break -- all at home. The Reds allowed 10 or more runs in four of them.
"The problem is clear," manager Bryan Price said. "Unfortunately, we've given up double figures in runs in four of these games. That's the constant thing. We need to pitch better. It's a worn-out record. I'm tired of talking about it."
ANOTHER NEW LOOK
Lovullo went with a different batting order for the second game in a row, giving his reserves a chance to play in a day game coming off an 11-inning night game. "In this case we've got guys who have been sitting on the bench watching and they're fully energized," he said.
Billy Hamilton doubled in the first inning and was thrown out by catcher Chris Iannetta while trying to steal third. It was the second time in two games that Hamilton was caught stealing. He's been caught seven times and has stolen 40 bases, most in the majors.
GOING, GOING …
The Reds have given up 166 homers, the most in the majors. They're on pace to break their major league record of 258 allowed last season.
Paul Goldschmidt went 0 for 5 with four strikeouts, ending his hitting streak at 11 games. It also ended his road hitting streak at 17 games, one shy of the Diamondbacks record.
Walker was placed on paternity leave, and RHP Matt Koch was recalled from Triple-A Reno. Lovullo will rearrange his weekend pitching plans with Walker gone, and he might use Koch to start one game.
Diamondbacks: Martinez was out of the lineup with the bruised hand, sustained in his second at-bat on Wednesday night. "A crazy 24 hours," he called it while headed to get treatment on Thursday morning.
Reds: SS Zack Cozart got a day to rest. He missed time last month because of a strained right thigh that is not fully healed.
Diamondbacks: Arizona opens a three-game series Friday against visiting Washington. The Diamondbacks lost two of three at Nationals Park in May and are 3-7 against the Washington during the last two seasons.