Houston, TX -- (Sports Network) - Doug Mientkiewicz went 4-for-4 with a pair of runs batted in, and the Pittsburgh Pirates won a wild, 8-7, decision over the Houston Astros in the finale of a three-game series at Minute Maid Park.

Jason Bay belted a two-run home run for the Pirates, who pulled off a sweep of Houston on the heels of a five-game losing streak. Xavier Nady and Freddy Sanchez each went 2-for-5, while Nate McLouth reached base three times and scored twice.

Franquelis Osoria (4-3) tossed two perfect innings to earn the win in relief of Ian Snell, who was battered for five runs on six hits in three innings. Damaso Marte worked a scoreless ninth to notch his fifth save.

Mark Loretta went 3-for-5 with two RBI for the Astros, losers of four straight after a four-game win streak. Kaz Matsui homered, drew three walks and scored three times, while Brad Ausmus added an RBI double.

Geoff Geary (2-2) was tagged for two runs in two innings and dropped the decision behind Brian Moehler, who was rocked for six runs -- five earned -- on nine hits in just 2 1/3 frames.

With the game knotted at 6-6, the Pirates forged ahead by two against Geary in the seventh. Singles by Ryan Doumit and Nady and a walk to Adam LaRoche loaded the bases with one out, and Mientkiewicz's single pushed the go-ahead run across. Pinch-hitter Jason Michaels then grounded into a force out that extended the gap to 8-6.

Houston pulled a run back in the bottom half on Geoff Blum's run-scoring single, but John Grabow came on in relief of Tyler Yates and retired pinch- hitter Darin Erstad to preserve the lead.

Grabow followed with a scoreless eighth, and Marte worked around a two-out walk to Ty Wigginton for the save, fanning pinch-hitter Miguel Tejada to complete the sweep.

The offenses started early, with each team rocking the opposing pitcher in the first. Pittsburgh ripped into Moehler, batting around and plating four runs. After a pair of singles to start the game, Doumit brought home a run with a sac fly. Bay followed with a long homer to left, and three batters later, Snell helped his own cause with an RBI single.

Houston responded with three runs against Snell, as the Astros loaded the bases with nobody out before Loretta's two-run single and Hunter Pence's run- scoring fielder's choice.

Pittsburgh tacked on another in the second when McLouth reached on a two-base error and scored on Freddy Sanchez's double, but Matsui's two-out solo blast in the home half pulled the Astros within 5-4.

Each team scored on back-to-back doubles in the third, with LaRoche and Mientkiewicz connecting for the Pirates and Wigginton and Ausmus picking up the hits for Houston.

However, Houston finally managed to keep the Pirates off the board in the fourth, then tied the game in their at-bat when Matsui walked, stole second and scored on Lance Berkman's single.

Game Notes:

It was the sixth four-hit game of Mientkiewicz's career...Each team went 4- for-14 with runners in scoring position...Nady extended his hit streak to 12 games...Bay's homer was the 138th of his career, tying Hall of Famer Bill Mazeroski for eighth on the Pirates all-time list...The teams combined to use 11 pitcher, six for Pittsburgh, five for Houston...The Pirates batted Snell in the eighth spot of the lineup, and between pitchers and pinch-hitters, eight different players occupied that spot in the batting order during the game.