HOUSTON (AP) -- J.D. Martinez has had a bad month at the plate.
The Houston Astros hope his big hit on Tuesday night will help turn things around.
Martinez had the go-ahead RBI single in the sixth inning and Jose Altuve had a solo homer to give the Houston Astros a 2-1 win over the Chicago Cubs .
The loss extends Chicago's losing skid to a season-long eight games.
Martinez hit .282 in April, but is 6 for 50 in May to drop his average to .219.
"There's no doubt that he's probably been pressing a little bit and trying to do a few things and it was a big hit," Houston manager Brad Mills said. "To come through at that time of the game and get that hit is definitely something (good)."
The hit by Martinez was the first for Houston since the first inning, but Justin Maxwell and Carlos Lee both drew two-out walks before it to set up the score.
"I was glad I was able to come through for the team tonight," Martinez said. "I know they've been behind me and they've been pushing me."
Houston starter J.A. Happ (4-3) allowed five hits and a run in six innings for the win. Closer Brett Myers pitched a perfect ninth for his 11th save.
Alfonso Soriano led off the fourth inning with a solo shot to left-center field that tied it at 1-1. The home run marked the first time in four games that Chicago had scored before the ninth inning. Soriano has had four homers in the last eight games, but is unhappy that none of those scores have helped the Cubs to a victory.
"The more important thing is to get wins," he said. "I don't know what we have to do to win one game and hit more, because right now we are struggling."
Altuve hit a leadoff home run to put Houston up early. It was his second career leadoff homer after his first career home run was an inside-the-park home run on August 20.
Jed Lowrie followed with a ground-rule double before Cubs starter Travis Wood (0-1) settled down and retired the next eight batters. Lowrie walked with two outs in the third inning before Wood sat down the next nine Astros.
He got some help from his defense on the second out in the sixth inning when Soriano robbed Lowrie of a hit with a nifty catch in left field. After the catch Soriano took the ball out of his glove and planted a kiss on it before throwing it back in.
Maxwell's walk after Soriano's catch chased Wood. He was replaced by Shawn Camp , who walked Lee before allowing Martinez's single to shallow right field.
Wood allowed two hits and two runs with three strikeouts in 5 2-3 innings in his second major league start of the season. He was recalled from Triple-A Iowa before Tuesday's game.
Houston third baseman Chris Johnson was ejected after slamming his helmet on the ground and arguing a call at first base in the fourth inning.
With the game tied at 1-1, Johnson hit a ground ball to shortstop Starlin Castro , who made a diving stop and whose throw to first appeared to barely beat Johnson. Johnson was called out to end the inning and immediately ripped off his helmet and slammed in to the ground while yelling at first base umpire Tim Tschida.
He was quickly thrown out of the game and was replaced Matt Downs for the fifth inning.
"I shouldn't have thrown my helmet," Johnson said. "I didn't say anything, it was just the helmet and he was (like): `See ya later."'
Reliever Wesley Wright pitched 1 1-3 hitless innings for Houston after Happ left before he was replaced by Wilton Lopez .
Lopez got into a jam in the eighth after allowing a single to Reed Johnson with one out. Johnson was replaced by pinch-runner Tony Campana , who went from first to third on an error by Lopez on a pickoff attempt.
The throw to third base arrived in time, but Downs had to leave the bag and go low to catch it, allowing Campana to dive over him Superman-style and crawl back to the base safely.
Campana's teammates were impressed with the play.
"That was unbelievable," Soriano said. "That (dive) that he made, that gave us the opportunity to tie the game, but we came up short."
Lopez ended the threat by striking out Castro and Soriano.
"The strikeouts are huge there," Mills said. "To do a job like that was absolutely outstanding."
NOTES: The Cubs placed C Welington Castillo on the 15-day disabled list with a sprained right knee to make room on the roster for Wood. ... Chicago manager Dale Sveum said he will miss Wednesday's game to attend his son's high school graduation in Arizona. Bench coach Jamie Quirk will fill in while he's gone. ... Houston center fielder Jordan Schafer returned to the lineup after missing the past two games with a right leg injury. ... Houston general manager Jeff Luhnow donned a uniform and scanned tickets at the gate and spent time as an usher on Tuesday night as part of the team's fan friendly initiatives. ... The Astros have signed RHP Armando Galarraga to a minor league contract and he will work out at the team's spring training facility in Florida until he's ready to join Triple-A Oklahoma City. Galarraga is best remembered for pitching a near perfect game which was ruined by an incorrect call in June 2010 for the Tigers against Cleveland.