Anthony Rizzo belted a monster leadoff home run in the fourth, Darwin Barney had three hits and fell a triple short of a cycle, and Scott Hairston added a solo shot in the sixth to power the Cubs, who are 7-2 against American League teams this year.
Garza set season highs in innings pitched and strikeouts, and posted his third quality start -- second in a row. Among the four hits off the right-hander was a leadoff home run by Chris Carter in the seventh.
"His fastball had life and [he had] command of it, down and away, and in," Cubs manager Dale Sveum said. "He got his ground balls. His slider got better as the game went on. He did a great job."
In his last two starts, Garza's given up one earned run over 15 innings. There were plenty of scouts who waited out the three-hour, 18-minute rain delay at the start of the game to see him in person. The non-waiver Trade Deadline isn't that far away.
"You don't want to lose a guy who can give up one run in his last 15 innings," Sveum said. "Obviously, it's a business, and that's not part of my business."
Garza has been rumored to be dealt his entire career. This year is no different.
"I'm looking forward to the next five days," Garza said, staying focused on the task at hand. "I think I face Milwaukee in Milwaukee, and I'll be ready."
He was matched up for the second straight game with catcher Dioner Navarro, who was his teammate with the Rays, rather than Welington Castillo.
"[Garza] better listen to me," Navarro said, laughing.
Navarro then complimented Castillo for the job he's done. Bottom line, Garza is the one on the mound.
"I've got nothing to do with it -- he's the one pitching and he's the one throwing the ball," Navarro said.
Garza, who struck out eight, missed a chance for a complete game after he walked Jose Altuve to open the ninth. Kevin Gregg took over, and closed things out for his 11th save in as many opportunities.
"I think [Garza] had all three pitches working for him, and he threw them all for strikes and he threw them in different counts," Astros manager Bo Porter said. "He did a great job of attacking our hitters."
Navarro said it was just a matter of time for the right-hander.
"He didn't have Spring Training," Navarro said of Garza, who strained his left lat during a live batting-practice session Feb. 17. "He didn't have what every other pitcher in the league had. At the beginning, he was trying to get into a groove, and his last couple starts, his fastball command has been off the charts, and that's the key for anybody."
"Ten months off is a long time," said Garza, who missed the second half of last season because of an elbow injury that flared up in mid July. "No excuses for the first five [starts this year]. It was just kind of finding my way again. Stuff's getting more fluid and free and easy, and I'm not forcing a lot of stuff."
The Cubs and Astros first met in 1962, and Chicago compiled a 184-169 edge in the series when both were in the National League. This was Houston's first trip to Wrigley Field as an American League team. Chicago wasn't a very good host. Rizzo launched the first pitch from Houston starter Dallas Keuchel in the fourth over the right-field bleachers. It was his first home run since May 18, and fifth of the season off a left-handed pitcher. He has six off right-handers this year.
Barney singled in the first, doubled in the third and hit his fourth home run in the fifth. In the seventh, he flied out to center -- and don't think there weren't a few players hoping the ball would drop so Barney had a chance at the cycle. The Cubs' just-completed four-game series against St. Louis helped him.
"I'd be lying if I said I didn't learn something watching those Cardinal hitters as well," Barney said. "They just have a good approach."
Hairston connected off Keuchel with one out in the sixth. The Cubs have hit 49 home runs at Wrigley, and are second in the NL in home runs at home. The Rockies lead the field with 51 homers at Coors Field. Ten of the Cubs' last 15 home runs have been solo shots.
"That's the way we've scored all year -- slugging percentage and home runs," Sveum said. "Even though we have gone through 2 1/2 months of seeing a lot of pitches, we still don't seem to get the walks. That's how we score -- home runs and doubles."
It was enough for Garza.
"I feel like everything is coming back, slowly but surely," he said. "Everybody would like it a lot faster, but as long as it comes back, I'm not worried about it."