Maholm's 7 effective innings, Alvarez's 2-run double lead Pirates past Astros 9-3

Paul Maholm limited Houston to one run over seven innings to win consecutive starts for the first time all season, and the Pittsburgh Pirates turned catcher Jason Castro's throwing error into their first two runs during a 9-3 victory over the Astros on Sunday.

Maholm (9-15) avoided adding to his NL-leading loss total, permitting Carlos Lee's two-out RBI double in the first before shutting out Houston over the next six innings. The left-hander was coming off a 5-2 victory over St. Louis on Tuesday in which he gave up two runs over seven innings for his first win since Aug. 3.

Houston starter J.A. Happ (6-3) held the Pirates scoreless on two hits over five innings before walking Garrett Jones and allowing Pedro Alvarez's single in the sixth. Jones took off from third on Ronny Cedeno's grounder to third baseman Chris Johnson, who had plenty of time to get the runner at the plate only to have Castro mishandle the throw.

Alvarez, who wound up at third, then scored on Andy LaRoche's sacrifice fly. LaRoche drove in his second run in as many games after previously not having an RBI since July 21.

Neil Walker drove in three runs as the Pirates scored three times in the seventh and four in the eighth against Houston's bullpen, with Alvarez and Walker each having two-run doubles. Alvarez has 13 RBIs in six games.

Hunter Pence hit his 25th homer for Houston in the eighth against reliever Evan Meek, making it 5-3 before the Pirates came back with four runs in the bottom half of the inning. Pence went 2 for 3 to raise his season's average against Pittsburgh to .472 (25 for 53) with four homers and 14 RBIs.

Happ wound up taking the loss despite limiting Pittsburgh to four hits, all singles, striking out four and walking two over six innings. Happ is 3-1 in his last seven starts, but Houston has lost each of his last four.

The Pirates (55-100) went 7-2 on their final and most successful homestand of the season, avoiding a 101st loss that would have guaranteed them their worst season since they lost 104 games in 1985.

They went 40-41 at PNC Park but are 15-59 away from home, putting them on pace for the NL's worst road record since the 1963 Mets went 17-64. The 1962 Mets (18-62), are the only other club in either league during the expansion era to win fewer than 20 road games during a 162-game season.

Pittsburgh, which plays three in St. Louis starting Monday and four at Florida after that, has lost 45 of its last 51 road games and has been outscored 432-228 away from home.

Notes: Maholm had a 1.82 ERA while going 2-2 in four starts against the Astros. He is 6-1 against them in eight starts at PNC Park. ... Despite losing the final two games of the three-game series, the Astros finished 11-4 against Pittsburgh. ... Houston CF Michael Bourn (oblique) sat out his seventh consecutive game. ... The Pirates averaged 19,919 while drawing 1,613,399 in 81 home dates, up slightly from 1,577,853 in 2009.