HOUSTON (AP) -- Houston interim manager Tony DeFrancesco isn't in a position to worry about anybody else's fortunes while trying to improve a team with the worst record in the majors.
And after the Astros knocked off the Pittsburgh Pirates 7-1 on Friday night, he bluntly conveyed that point.
''I know they've been struggling and they keep talking about getting to .500 and the history of Pittsburgh,'' he said. ''For me, I don't feel bad for anybody right now. We're going to go out and try to compete and try to win series until the end of the season here.''
Jed Lowrie hit a three-run homer and Justin Maxwell and Brett Wallace added solo shots to help the Astros coast to the win, further dampening the Pirates already dim postseason hopes.
The Pirates couldn't find much offense as they lost their fourth straight game to fall to six games back for the second NL wild card spot. They've lost 16 of their last 20 games in this late-season swoon to fall to 74-76 and increase the possibility of a 20th straight losing season, which would extend their major North American professional sports record.
Things looked good for the Pirates on Aug. 8 when they were 63-47, a season-best 16 games over .500.
''When you don't get the results you want and you don't run the bases, it doesn't look good,'' Pirates manager Clint Hurdle said. ''Sometimes the game can look heavy on you. That's when I have to make sure I am getting the effort and the attitude we need. We are, but we just aren't getting the results come game time.''
Houston starter Edgar Gonzalez lasted just 1 2-3 innings before leaving with a strained right hamstring. That forced the Astros to use six different relievers to cobble together the rest of the game. The bullpen combined to fan 11 and allow six hits. Fernando Rodriguez (2-10) struck out four in a career-high 3 1-3 innings for the win.
''Fernando Rodriguez really stepped up today,'' DeFrancesco said. ''He got some big outs for us, filled some innings for us. He made some pitches ... I'm real pleased with the way the bullpen handled the situation.''
Pittsburgh starter Jeff Locke (0-2) yielded three hits and three runs with a career-high eight strikeouts in five innings. He is 0-5 in eight career major league starts.
Garrett Jones allowed the Pirates to avoid a shutout with his solo homer off Rhiner Cruz in the eighth inning.
Brandon Barnes singled to right field before Maxwell drew a two-out walk in the first inning. Lowrie followed with his 15th homer and first since June 26, a shot to the Crawford Boxes in left field. He was on the disabled list from July 15 to Sept. 12 with an injured nerve in his right leg.
Locke was lifted to start the sixth for James McDonald, who was moved out of the rotation on Sunday after a second half filled with struggles.
McDonald was 9-3 with a 2.37 ERA before the break, but entered the game 3-5 with a 7.08 ERA since then.
A change of pace didn't yield different results for McDonald in his first relief appearance since 2010.
Maxwell knocked his solo shot to left field to push the lead to 4-0. Things continued to unravel after that when he plunked Lowrie, before a standup RBI triple by Wallace. Wallace's first triple this season rolled into the corner of right field to extend the lead to 5-0.
McDonald's night ended when he walked pinch hitter Brian Bogusevic. Bryan Morris came on to get the first out of the inning. Then he walked pinch-hitter Scott Moore to load the bases before hitting Jose Altuve with a pitch to send a run home and stretch Houston's lead to 6-0.
Wallace hit a two-out, two-strike homer off Hisanori Takahashi which landed in the bullpen in right-center to pad the lead in the seventh.
He was impressed by the power the Astros showed on Friday.
''It's awesome. It shows what we can do,'' he said. ''We have a lot of guys that can hit homers and drive in runs and I think it's just a matter of us all getting on the same page and doing it every night together ... if we can all get on the same schedule and start doing it together, I think our offense becomes that much more dangerous.''
NOTES: Pittsburgh 2B Neil Walker was out of the lineup again with a sore back. He played on Thursday after missing two of the previous three games with the issue. ... The Astros, who began as the Colt .45s, continued the celebration of their 50th anniversary by wearing throwbacks fashioned after the original Colt .45 uniforms for the third time this season. The white uniforms featured the word ''Colts'' in orange lettering with a pistol below it. ... These teams continue the series on Saturday when Pittsburgh's Kevin Correia opposes left-hander Dallas Keuchel.