Pirates 8, Astros 7: Drew Sutton belted a walkoff solo home run with one out in the ninth inning as host Pittsburgh won for the sixth time in seven games.
Andrew McCutchen went 3-for-4 with a homer and two RBIs, Garrett Jones added a two-run blast and Pedro Alvarez also drove in a pair of runs for the Pirates, who overcame a 6-2 deficit to post their fifth win in six home contests.
After Pittsburgh rallied to take a 7-6 lead, closer Joel Hanrahan (4-0) suffered his third blown save of the season by allowing an RBI double to pinch hitter Jason Castro with two outs in the top of the ninth. The Pirates would not be denied, however, as Sutton completed a 3-for-5 performance with a blast off Wesley Wright (0-2), his first homer since 2010 with Cleveland.
Jones began the Pirates' comeback as he led off the sixth inning with a single and scored on Casey McGehee's base hit two batters later. Batting for Clint Barmes later in the frame, Alvarez drew Pittsburgh within 6-5 with a two-run single up the middle.
McCutchen hit a one-out single in the seventh and Jones followed with his 12th blast of the season off Brandon Lyon to put the Pirates ahead. Jones is 6-for-9 with two homers and six RBIs through the first two contests of the four-game series.
The comeback helped preserve starter A.J. Burnett's eight-game winning streak. The right-hander, who had won his previous eight starts, was tagged for six runs and 12 hits over five innings.
Jordan Schafer and Jed Lowrie each had two hits and two RBIs for the Astros, who have lost six straight overall and eight in a row on the road.
GAME NOTEBOOK: Pittsburgh LF Alex Presley left the game after four innings with concussion-like symptoms. ... Houston fell to 9-30 on the road, the worst record in the major leagues. ... Pittsburgh, which has homered in 11 straight games, is a National League-best 25-13 at home. ... The Pirates sent Jose Tabata to Triple-A Indianapolis prior to the game and recalled fellow OF Gorkys Hernandez. Tabata, who signed a contract extension last year that runs through 2016, was hitting just .230 with three home runs and 11 RBIs in 72 games this season.