Updated

On a night when Houston severed the last tie with the past by trading away the final member of their 2005 World Series team in ace Wandy Rodriguez, rookie Lucas Harrell gave the Astros a glimmer of hope for the future.

Harrell allowed seven hits and a run in seven innings, but the Astros dropped their eighth straight game, 4-2 to the Cincinnati Reds, after a blown save by Francisco Cordero on Tuesday.

Drew Stubbs hit a go-ahead homer and the NL Central-leading Reds rallied for three runs in the ninth inning against Cordero, a former teammate, to tie their longest winning streak of the year at six.

"He's been so valuable all year long," Houston manager Brad Mills said of Harrell. "He's just taken the ball and run with it. Just like you want to see guys do. This guy's done a great job and has been a blessing to our rotation."

Harrell has gone 5-1 with a 1.89 ERA in eight starts in Houston. His last three starts overall have been solid and he has a 1.42 ERA in that span.

Cordero got his first save chance since being acquired in a trade with Toronto last week. Stubbs hit a two-run homer for a 3-2 lead and Xavier Paul added an RBI single.

During the game, the last-place Astros announced the trade of Rodriguez to Pittsburgh.

Justin Maxwell's two-run homer in the fourth gave Houston a 2-0 lead. Brandon Phillips doubled and scored on Paul's single in the Cincinnati sixth.

Zack Cozart singled with one out in the Reds ninth and Stubbs hit his 10th home run. Jay Bruce drew a two-out walk, moved up on a wild pitch and after Scott Rolen walked, Paul singled.

Houston fans weren't impressed with their first look at Cordero (3-6), who received a loud chorus of boos from the paltry crowd. Cordero played for the Reds from 2008 until last year, when he finished with 37 saves.

"It was tough, not because I'm facing my former team, but because Lucas threw an unbelievable game and I had a chance to get a save and get us a W, but I didn't," Cordero said. "I made a mistake, Drew Stubbs hit it out and they won."

Cincinnati closer Aroldis Chapman allowed a hit in a scoreless ninth for his 18th save.

Reds starter Mike Leake (4-6) scattered seven hits with two runs over eight innings for his first win since his pitched a complete game on June 29.

The day marked the end of an era for the Astros, who sent Rodriguez and cash to the Pirates for Triple-A All-Star Rudy Owen and Colton Cain, both left-handers, and outfielder Robbie Grossman. Rodriguez was the fifth pitcher the rebuilding Astros have traded since Friday.

Leake walked Marwin Gonzalez to start the fourth. Chris Johnson singled with one out and Gonzalez was thrown out trying to reach third. Maxwell followed with his home run.

Houston has lost 21 of its last 23 games, but took this one a bit harder than some recent losses because they led most of the way.

"They're all tough, but this one a little more because we were in the game," Johnson said. "We were playing good behind Lucas. Lucas did a great job tonight so this is a tough one."

NOTES: Houston C Jason Castro, on the DL with swelling in his right knee, is improving but isn't quite ready to return to the team. ... Reds starter Mat Latos was OK on Tuesday after spraining his left ankle in the fifth inning of Monday night's win over the Astros.