HOUSTON -- Drew Stubbs isn't where he wants to be despite returning from the disabled list almost a month ago.

The Cincinnati center fielder hopes Tuesday night's performance is an indication that things are starting to come together for him.

Stubbs hit a go-ahead homer and the Reds rallied for three runs in the ninth inning against former teammate Francisco Cordero, beating the Houston Astros 4-2 and tying their longest winning streak of the year at six.

The NL Central-leading Reds sent Houston to its eighth straight loss.

Stubbs has struggled to get going since a stint on the disabled list in June with a strained left oblique.

"It's a process," he said. "It's not an overnight thing. I think you have to string together a few weeks of that to really get to feeling good and this is a start. Hopefully, I can climb back to where I need to be."

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.

The Reds are relying on a handful of players to step up and pick up the slack while star Joey Votto is out for a month recovering from arthroscopic knee surgery. Cincinnati manager Dusty Baker believes Stubbs can be someone to help fill the void.

"I see the ability there," Baker said. "He wasn't a No. 1 draft choice for nothing. It frustrates him, for sure, quite often. It frustrates us, too, because we know it's there. Boy, I would just love to see him get going. It would make it a lot easier."

During the game, the last-place Astros announced they had traded pitcher Wandy 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.

Astros rookie Lucas Harrell allowed seven hits and a run in seven innings.

"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."

Stubbs thinks Cincinnati's familiarity with Cordero may have helped on Tuesday night.

"Playing with him for 2½ years, you stand behind him and watch him pitch a lot," Stubbs said. "Obviously, we have the scouting reports, but it helps whenever you play behind a guy for a few years."

Paul finished with three hits.

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.

"That is a great comeback though because Harrell threw the ball great," Baker said. "Leake threw the ball great. He made one mistake. He hung the breaking ball to Maxwell. Other than that, he was masterful. We tried to stay with him as long as we could ... he was saving my bullpen. We tried to get him the victory. Every once in a while, you try to do the right thing and it works."

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 only player on Houston's roster remaining from their 2005 trip to the World Series and the fifth pitcher the rebuilding Astros have traded since Friday.

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.