Left-hander Jonathan Sanchez can relate.Sanchez tries again for his first win away from home Tuesday night when the Giants look to avoid yet another road loss and a sixth in a row against the Houston Astros.San Francisco (58-48) entered the opener of this three-game series tied for the NL wild card lead in large part because it has the best home record in the majors at 37-16. The Giants went 6-1 on their first homestand of the second half, taking three of four against NL East-leading Philadelphia over the weekend.San Francisco's success at home, however, has been largely negated by its struggles on the road. The Giants are 21-32 outside San Francisco, including 3-8 since the All-Star break.They went 2 for 10 with runners in scoring position in a 4-3 loss to the Astros on Monday night, their fifth consecutive defeat at Minute Maid Park since the start of last season."We didn't cash in on the opportunities," manager Bruce Bochy told the Giants' official Web site after his club fell a half-game behind idle Colorado in the wild card race. "We had their guy on the ropes a few times but couldn't get another hit to put a crooked number on the board."Sanchez (4-9, 4.81 ERA) knows all about struggling on the road. He's 4-1 with a 3.26 ERA in nine games at AT&T Park, where he pitched the majors' first no-hitter of the year on July 10.In nine starts away from home, however, he is 0-8 with a 6.60 ERA. He's lost 13 of his last 14 road decisions dating to July 9, 2008.Sanchez won his last start Thursday in San Francisco, holding the Phillies to two runs and three hits while striking out seven in 5 2/3 innings of a 7-2 victory.Sanchez is 0-2 with a 2.89 ERA in three career games -- one start -- against the Astros. The losses came in his two games at Minute Maid Park.Houston (53-53) has won back-to-back games after dropping seven of eight. Geoff Blum and Kaz Matsui homered off Matt Cain -- who was 3-0 with a 0.86 ERA over his last five starts -- to lead the Astros to Monday's victory."Guys like that have to make mistakes in order for you to beat them," said Astros manager Cecil Cooper, whose team has scored more than three runs only twice in its last 10 games. "You don't get a whole lot off guys like that. We made it all count."The Astros hoped to be able to turn to their ace Tuesday, but Roy Oswalt is still feeling pain from an irritated disk in his back. Houston has recalled Felipe Paulino (2-5, 7.04) to start in his place.Paulino made his last start in the majors July 3 against the Giants, giving up nine runs and nine hits in two innings of a 13-0 road loss. He followed that with a bad relief appearance before getting sent down.The right-hander has no record and a 3.86 ERA in three starts with Triple-A Round Rock since his demotion.