CHICAGO -- Jason Hammel is certain the Cubs are better than their record so far.
"With a doubt," he said. "We've played a lot of close ballgames where we could have come out on the other end. We're a young team and we'll figure out how to win those ball games pretty soon."
Hammel (3-1) allowed just one run and four hits without walking a batter in seven innings to lower his ERA to 2.60.
"Very nice job," Cubs manager Rick Renteria said. "He got some groundball double plays when he needed to. Made some pitches when he needed to. It was pretty efficient."
Olt still is hitting below .200 for the season (.195), but has four homers and nine runs batted in despite not playing every day.
The Cubs, who've won three of four to improve to 7-12, have won back-to-back games for the first time this season. They last won consecutive games on Sept. 9 and 10 of last season against the Cincinnati Reds. Their last consecutive home wins came on Sept. 4 and 6 against Miami and Milwaukee.
Brandon McCarthy (0-4) lowered his ERA from 7.11 to 6.23 because only one of five runs allowed was earned. He yielded seven hits in five innings.
Arizona has dropped four straight and has the worst record in the majors at 5-18.
"It was a carbon copy of the game (Monday)," Arizona manager Kirk Gibson said. "We made an error there, gave them life and then Brandon got behind in the count 3-1 and Olt hit a ball down over the plate, a pretty big pop into that wind.
"We didn't mount any pressure again offensively so I don't know what to tell ya," he said.
In the third inning, Luis Valbuena stroked a one-out double to left-center field and then scored two batters later on a two-out single by Schierholtz.
In the fifth, Schierholtz drove in Valbuena again, this time on a sacrifice fly to right field, for a 2-0 lead.
The Cubs took advantage. Given the extra out, Starlin Castro singled to put two runners on and Olt followed with a homer into the right field bleachers for a 5-0 lead.
"I think it probably helped me," Olt said of the wind. "I wasn't trying to hit a home run. I was just trying to put the ball in play and hit it hard."
Arizona finally got on the board against Hammel in the sixth when Tuffy Gosewisch led off with a homer.
The Cubs then broke things open with four runs in the bottom of the eighth, while the Diamondbacks got one back in the ninth.
Wednesday is the 100th anniversary of the first game at Wrigley Field, which then was known as Weeghman Park, between the Chicago Federals and Kansas City Packers of the Federal League. The Cubs will wear replica Federal uniforms for the game, while Arizona will wear Packers uniforms. . Diamondbacks OF Mark Trumbo didn't start because of soreness in his left foot. The injury occurred late in Monday's game. . Now that RHP Jose Veres no longer is closing games, Renteria will hunt for opportunities to get Veres on the mound so he can work out his problems. "It could be at any moment," Renteria said. "We could be up by 10 (or) down by 10. He needs to pitch. He's talked about he wants to get back on the mound and throw." . LHP Wade Miley (2-2) is scheduled to face Chicago RHP Jeff Samardzija (0-2) on Wednesday.