"We were able to come through with big two-out hits," Olt said. "That's how you win ballgames."
That, and having Wood recover from a first inning in which he walked the bases loaded with two outs. The lefty scattered two hits over seven innings to improve to 3-1 in five home starts with a 2.43 ERA. He's now served up nine earned runs over 33 1/3 innings at Wrigley. The lefty is 1-3 with an 8.02 ERA in four road outings.
Wood walked the bases loaded in the first, then got Khris Davis to hit into a fielder's choice to end the inning.
"It was a struggle in the first," Wood said. "We weren't missing bad, but we were missing. It was a minor adjustment that we had to make."
The trouble was that he was flying open in his mechanics, and once corrected, he shut down the Brewers. The lefty retired the next 10 batters he faced before Logan Schafer doubled with one out in the fifth. One out later, Rickie Weeks launched a 2-0 pitch from Wood over the bleachers in left-center field for his second home run.
"He didn't make any mistakes really," Weeks said of Wood. "The one mistake he made, I hit the ball out. Other than that, the cutter in, he was spotting it dead on under the hands. He was painting that little sinker away. You can't do too much about that when a pitcher is going like that."
The Cubs had the lead before Weeks' blast, going ahead 2-0 in the second when Luis Valbuena walked to set up Castillo's fifth home run, which landed in the first row of the left-field bleachers.
With two outs in the third, Starlin Castro and Valbuena hit back-to-back doubles to open a 3-0 lead. It's an encouraging sign for the Cubs, who entered the game batting .190 with runners in scoring position and two outs. Olt made it 4-0 with a leadoff homer in the fourth, his ninth, which leads the team and all National League rookies.
Olt is the first Cubs rookie to hit nine home runs before June 1 since Geovany Soto did so in 2008. Soto won the NL Rookie of the Year that season.
"I've just gotten some good pitches to hit," Olt said. "As long as I'm doing that, I'm happy. The home runs come in bunches. Hopefully, I can keep it going."
He's not thinking about the numbers.
"I'm more worried about putting together good at-bats in a row," Olt said. "I feel I've had a couple good ones in a row, and then give away at-bats. I'm not worried about numbers now. It's a long season."
He also helped Wood with his glove when he grabbed Weeks' popup along the railing near the Cubs' dugout for the first out of the game.
"That almost fell out, too," Olt said. "Luckily, Castro was there and helped out a lot and let me know when the wall was there and helped me find the ball. I definitely owe him. I got lucky it landed in the web."
Closer Hector Rondon survived a scare in the ninth, too. He gave up a double to Ryan Braun, but locked down his fifth save in as many opportunities.
"Like I've said, I'll be ready for any situation," Rondon said. "If they want to put me in the second inning, third inning, whatever situation, I'll take it."
The Cubs wore retro 1937 uniforms as part of the team's continuing celebration of Wrigley Field's 100th anniversary. The Brewers, who didn't exist in '37, still have a solid lead in the NL Central. It's just another step for the Cubs.
"Any time you can win a series it's big," Wood said. "Hopefully, we can take it in stride, and keep it rolling."