HOUSTON -- Jeff Keppinger found a quick way to endear himself to his new team: He won a game in his first at-bat.
It was Keppinger's first game with the team after being acquired from the Reds. He batted .140 for Cincinnati this spring.
"It's definitely a good welcome and hopefully I can keep doing it," Keppinger said.
Ivan Rodriguez opened the bottom of the 10th with an infield single down the third-base line, his first hit with Houston after starting the season 0-for-7. Lance Berkman followed with another single off Neal Cotts (0-1) before Cubs manager Lou Piniella brought in Gregg.
Keppinger snapped his bat and stumbled out of the box on his grounder between third and shortstop that scored Rodriguez.
"It's always nice to contribute," Rodriguez said. "Keppinger came late, I came late and we are both helping the team win ballgames and that's why we're here."
Houston earned its first win of the season after the Cubs won 4-2 on Monday behind Carlos Zambrano.
Soriano's homer bounced off the railroad tracks atop the wall in left-center. He also homered on the second pitch of Monday night's game.
Bourn put the Astros on top 2-1 with his RBI single in the sixth.
Pence tied it at 1 with a homer to left-center in the fifth. It landed in a section of Berkman fans who dress up in puma costumes in honor of the slugger's nickname, "Big Puma." The group of more than a half-dozen waved the paws of their mustard yellow and white costumes and jumped around wildly as Pence circled the bases.
Dempster sailed through the first few innings and didn't allow a hit until a single by Tejada with two outs in the fourth.
"Dempster did a nice job," Piniella said. "He gave us six good innings. We just didn't score any runs."
Dempster, who had a career-high 17 wins and made the All-Star team last season, gave up six hits and two runs with five strikeouts in six innings.
"I felt good," he said. "For the most part I liked the way I threw the ball. I just wish the results would have been better. We were right there. We had a chance."
Angel Guzman struck out two in a scoreless seventh for the Cubs.
Astros starter Wandy Rodriguez allowed four hits and one run in six innings. He struck out four and walked three.
"It was a beautiful game today," he said. "We won. That's all we want. Today I felt great."
"I overexposed my shoulder on a throw," Soto said. "After that I just felt bad. It's the same thing that happened earlier in the spring. But if I just stay on top of my exercises I'll be all right in a couple of days."
The Astros commemorated the 10th anniversary of Minute Maid Park with a pregame ceremony featuring a player or coach representing each year. Those involved in the ceremony included Larry Dierker, Jeff Kent and Phil Garner. ... The Cubs will participate in three home openers this season. They opened Houston's home schedule on Monday, will do the same in Milwaukee on Friday and finally open their home schedule next Monday. ... Tuesday was the first time in his career that Ivan Rodriguez caught for another Rodriguez.