PITTSBURGH - Like many Houston Astros, Jimmy Paredes is learning on the job.
Paredes is in his second season as an outfielder after playing beginning his career as a shortstop in the minor leagues then moving to third base.
Paredes' inexperience showed for the second time this week on Friday night as his error with two outs in the bottom of the ninth inning enabled the Pittsburgh Pirates to rally for a 6-5 victory over the Astros at PNC Park.
In a season in which little has gone right for the Astros, they suffered yet another difficult loss Friday night.
Paredes dropped Russell Martin's two-out fly ball with the bases loaded in the bottom of the ninth inning as the Pittsburgh Pirates rallied for a 5-4 victory at PNC Park. The ball got jarred loose when Paredes and second baseman Jake Elmore bumped into each other.
On Monday in Detroit, Paredes was part of a similar play when he collided with second baseman Jose Altuve on a pop fly that wound up dropping.
"It's not a lack of communication, because there's only one person that should be communicating," Houston manager Bo Porter said. "The infielder is not saying anything. If he gets underneath the ball, the outfielder is running in and he's looking at the infielder, and if the infielder is waving his hands and under the ball, you let him take the ball."
Paredes explained the play from his perspective as he finished dressing in the quiet Astros' clubhouse.
"I'm anticipating the ball being hit to me, just like I do on every pitch," he said. "All I'm thinking about is catching the ball for the third out. That's all I wanted to do. I was watching the ball and then I hit into (Elmore). Sometimes things like that happen in this game, and it's frustrating to lose like this."
Slumping Pittsburgh third baseman Pedro Alvarez hit a long two-run home run in the bottom of the eighth inning off Hector Ambriz to tie the score at 4-4. The drive was estimated at 462 feet as it cleared the right-field stands and went into the Allegheny River on one hop.
A night earlier, Pirates right fielder Travis Snider hit a 458-foot homer against Milwaukee that rolled into the river. Alvarez had gone 6-for-35 in the previous 10 games.
"I'm not going to take credit if it bounces in," Alvarez said. "That's cheating."
Only one player has ever hit the river on the fly since PNC Park opened in 2001, Houston's Daryle Ward connecting off Kip Wells in 2002.
Starling Marte led off the ninth with a single off Edgar Gonzalez (0-1), but he was forced at second. A line single by Andrew McCutchen put runners at first and third and Gonzalez then blew a chance to start an inning-ending double play when he dropped Brandon Inge's comebacker.
With the bases loaded, Neil Walker struck out looking on a 3-2 pitch but then the Astros misplayed Martin's ball as they lost for the seventh time in eight games. They have the worst record in the major leagues at 11-31.
"Our defense has been one of our strong suits pretty much the whole year, but tonight we did not play good defense and we put ourselves in position where it cost us the ballgame," Porter said.
The Pirates won for the seventh time in their last eight games and moved a season-high eight games over .500 at 25-17.
"This game's crazy sometimes," Pittsburgh manager Clint Hurdle said. "The crowd helped us there on the error. They made it tough on the fielders and they created a break for us."
McCutchen had three hits and a home run for Pittsburgh and Martin and Alvarez had two hits each. Justin Wilson (4-0) worked a scoreless ninth for the win.
Matt Dominquez homered for Houston.
Houston starter Jordan Lyles remained winless against Pittsburgh in six career starts despite holding the Pirates to two runs - one earned - in five innings. Lyles is 0-4 with a 6.75 ERA versus the Pirates.
Pirates starter Jeanmar Gomez gave up four runs -- three earned -- and five hits in 4 2/3 innings. He had gone 1-0 with a 1.93 ERA in his first three starts after beginning the season in long relief.
The Pirates scored a run in the sixth to get within 4-2 when right fielder Chris Carter, normally the Astros' designated hitter, dropped McCutchen's fly ball for a three-base error and Garrett Jones followed with a double. DH rule was not in effect with the game being played in an NL ballpark.
Dominguez's solo shot off into the left-field bleachers off Gomez in the fifth started a three-run inning that enabled Houston to move in front 4-1. Elmore had an RBI single and a run scored on a throwing error by Walker, the second baseman.
Houston's Robbie Grossman led off the game with a double that rolled to the 410-foot notch in left-center field, moved to third on Elmore's sacrifice bunt and scored on Jason Castro's sacrifice fly. Grossman was one of three prospects traded by the Pirates to the Astros last July for left-hander Wandy Rodriguez.
McCutchen answered in the bottom of the first with a solo home run to center field, his sixth homer of the season, off Lyles, to draw Pittsburgh into a 1-1 tie.
NOTES: Houston manager Bo Porter decided to give Bud Norris two extra days off before his next scheduled start. The right-hander will pitch May 21 against Kansas City instead of Sunday at Pittsburgh. Norris left his previous start on Tuesday at Detroit with lower back spasms while warming up for the sixth inning. Right-hander Lucas Harrell will pitch Sunday against the Pirates and left-hander Dallas Keuchel will start Monday against the Royals, both moving up one spot in the rotation and pitching on the normal four days of rest. ... Altuve will be activated from the bereavement list before Saturday night's game with the Pirates and Elmore is expected to be optioned back to Triple-A Oklahoma City. Elmore started all three games at second base after being called up Tuesday when Altuve was placed on the bereavement list. ... Pittsburgh placed right-handed reliever Jose Contreras on the bereavement list and recalled right-hander Jared Hughes from Triple-A Indianapolis. ... Houston left-hander Erik Bedard (0-2, 6.670 will face A.J. Burnett (3-4, 2.73) on Saturday night. Bedard was the Pirates' opening-day starter last season and Burnett had the honors this season. Pittsburgh released Bedard last Aug. 30.