The Cubs, who boast what Lackey called "a legit lineup," pounded 14 hits off five D-backs pitchers in a 14-6 come-from-behind win.
"I kept giving the lead back in the first couple innings, which wasn't ideal," said Lackey, who allowed six runs on eight hits in six innings with four strikeouts and a walk. "Then I started mixing things up and got in a little groove later on in the game. You definitely know with our offense, you don't have to be perfect, but I'd like to be better than that."
Since undergoing Tommy John surgery in 2011, Lackey has come back strong.
"I'm really seeing a renaissance," Cubs manager Joe Maddon said. "I think this is the third year [since the surgery], and watching him the last couple years, I was really impressed with the arm stroke and command of his pitches. I watched him closely this spring and I liked everything about the way he threw the baseball."
When Lackey, 37, signed a two-year contract with the Cubs, Maddon was excited.
"I think it's going to be proven to be one of the best," Maddon said. "He's such a competitor. He's ready and he wants to win. That's where he's coming from. Everything is in order for him to have a really good season."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings. You can follow her on Twitter @CarrieMuskat and listen to her podcast. This story was not subject to the approval of Major League Baseball or its clubs.