PITTSBURGH -- Jeff Karstens is just going to close his eyes and hang on. The rags-to-riches ride he's on has taken him from an afterthought to being statistically among the National League's best.
Kind of like the team he plays for.
Karstens allowed one run in seven-plus innings, Brandon Wood homered and the surprising Pittsburgh Pirates moved into second place in the NL Central with their third consecutive win, 5-1 over the Houston Astros on Tuesday night.
"It's been one of those things where I'll ride the wave until it ends," said Karstens, who began the season in the bullpen and with a 12-27 career record but improved to 7-4 with a 2.55 ERA with his latest win.
"Hopefully it doesn't end, but I know at some point it's going to," he said. "It's one of those things where I'm going to have fun with it, and hopefully when that bump that comes in the road somewhere down the line, it's not too long."
Pittsburgh has to be feeling as if its riding a similar wave. These Pirates (45-41) are in uncharted waters, improving to four games over .500 this late in a season for the first time since 1992, the team's most recent winning season before a major North American professional sports record 18 straight losing seasons.
The Pirates are 1 1/2 games out of first -- the closest they've been to there this late in the season in 14 years. Pittsburgh did not win their 45th game last season until Sept. 3.
"We're having a blast," Wood said. "I haven't been here too long, but hearing from some of the guys, they haven't seen games like this in a long time. So we're going to try to keep banging it."
Karstens (7-4) allowed seven hits and struck out three, giving a Pittsburgh starter its 34th win this season. That matches how many the entire starting staff had in 2010.
Karstens threw 72 of his 95 pitches for strikes. He ranks fifth among all qualifying NL starters in ERA.
"He's not the kind of guy that scouts probably when they see them are going to drool over him," Pirates manager Clint Hurdle said. "He's not 6-4, 215 and cut. He knows how to play the game, he knows how to pitch, and he knows how to compete. I think that's his biggest strength out there -- the fact that he's fearless."
Karstens showed some of that fearlessness by laying down a textbook suicide squeeze bunt to account for Pittsburgh's final run in the sixth.
Clint Barmes went 2 for 4 with a homer for free-falling Houston, which has lost five straight and 10 of 11.
"It's definitely been hard," Barmes said. "We'll come out and be in a game for six or seven innings, and one thing happens and the game kind of gets out of control."
Wood entered Monday's series-opening Pirates victory in the fourth inning after Josh Harrison left the game following a collision at home plate. He likely would not have started Tuesday except that Harrison -- although he passed concussion tests -- was given an extra day of rest.
Wood, who has homered twice in his past four starts, was on base three times and had a run and three RBIs.
After Overbay singled to lead off the bottom of the second, Wood took the first pitch from Wandy Rodriguez into a sliver of seats in right-center for his fourth home run of the season.
Two innings later, Wood made it 3-0 with a two-out single that scored Walker, who had doubled.
Barmes' homer to left on a 3-2 count with one out in the fifth was his fourth of the season and first since June 4.
Barmes was the only hitter on whom Karstens went to a three-ball count against.
Rodriguez (6-5) was charged with five runs, eight hits and two walks with six strikeouts in six innings. He fell to 3-2 since returning from a stint on the disabled list with an elbow injury. Rodriguez hadn't allowed a run in three of his previous four starts.
"I had bad luck today," Rodriguez said. "I threw a lot of good pitches, but they hit the ball, broken-bat base hits. A bad day, but that's what happens some times."
Karstens entered the game with the fifth-best walks-per-nine-innings ratio in the NL. ... Pittsburgh has won six of its past seven at home and has a seven-game winning streak against Houston. ... The Pirates finished the 1992 season 96-66 and were NL East champions. ... Rodriguez had won his past four starts against the Pirates, having allowed a total of four earned runs in that time. ... Each of the three pitchers used by the Astros had the same surname. RHP Fernando Rodriguez worked a scoreless seventh on the day he was recalled from Triple-A, and RHP Aneury Rodriguez pitched a perfect eighth.