Wells (7-4) was winless in his first seven starts. In his first four, the Cubs scored a total of five runs while he was in the game. They surpassed that number in the first inning Wednesday, as Alfonso Soriano led a six-run charge with a three-run homer.
"It's always nice," Wells said of the support. "But I've been taught since I've been pitching that you can't let that relax you. You have to go out there like it's a 0-0 game no matter what the score is."
The Cubs entered play a half-game back in the National League Central behind the Cardinals, who play Wednesday night against the Dodgers. The Chicago bullpen had thrown nine innings over the past two games, and with no off-day until Aug. 6, manager Lou Piniella needed Wells to eat innings.
He did just that, tossing a career-high eight and giving up no runs on five hits, all singles.
"He's pitched exceedingly well," Piniella said. "I wonder where we'd be without him."
Wells struck out one but combined a good sinker with an effective changeup to record 17 ground-ball outs and three double plays.
"Today I was able to get some ground balls and some double plays when I needed them," Wells said. "I was able to get through some quick innings and get deep into the game."
The Cubs won for the sixth time in seven games. All eight starting position players had a hit for Chicago, which battered Houston starter Mike Hampton (6-8) for nine runs in four innings.
Derrek Lee came up with runners on second and third and no outs in the first and drove in the first run with a sacrifice fly. Aramis Ramirez followed with an RBI single, Soriano cranked a three-run homer to left, and Koyie Hill capped the frame with a run-scoring single.
"I just basically got my butt kicked," Hampton said.
Soriano is hitting .364 with a .652 slugging percentage and five home runs in 17 games batting sixth since Piniella moved him there earlier this month.
"I think he's settled in," Piniella said. "I think he's comfortable there. He's hitting the ball for power. He's driving in runs. His at-bats look a lot better, so I think he's found a home there in the middle part of the lineup."
Ramirez spent two months on the disabled list with a dislocated left shoulder, and his power did not come back immediately upon his July 6 return to the lineup. But he now has extra-base hits in seven straight games and is hitting .517 with four home runs during that stretch.
Ramirez extended Chicago's lead to 7-0 in the second when he belted a home run onto Waveland Avenue.
"Obviously it took him 10, 12, 14 days to get his stroke back, but now he's back," Lee said. "Mentally he had to get over the worry about his shoulder, but now he's over that and he's swinging the bat great."
The Cubs scored twice more in the fourth on Lee's RBI double and Milton Bradley's RBI single. Pinch-hitter Jake Fox added a sacrifice fly in the seventh.
If it was not already clear it was the Cubs' day, it became abundantly so in the eighth.
Andres Blanco squeezed a liner just inside the right-field foul pole for his first Major League home run in his 350th plate appearance. Micah Hoffpauir followed with his first career triple and scored on Fox's single to make it 12-0.
Rookie Mitch Atkins took over for Wells and threw a scoreless ninth in his Major League debut. Wells, who threw 110 pitches, said he wanted to go for the shutout but realized it was too early in the season to tax his arm like that.
Wells also was cautious about his outlook for the remainder of the season.
"I'm scared to get comfortable," he said. "I'm scared to get overconfident and have the wheels fall off. So I'm just going to ride it out as long as I can and hopefully keep pitching well and keep winning ballgames."