HOUSTON -- At the plate in the ninth inning with the game tied, Hunter Pence knew he had to find a way to help the Astros beat the Cincinnati Reds and end a four-game skid.

Pence came through, hitting a tiebreaking double to help the Astros avoided a series sweep with a 4-3 win over the Reds on Wednesday.

Mike Leake (3-2) walked J.R. Towles with one out in the ninth before Pence's full-count hit landed in the corner of right field and sent Towles home.

"The last couple of games have been pretty rough," Pence said of the first two games of the series where Houston was outscored 13-4. "We kind of came to a conclusion that ... we had to go out there and have fun and stay enthusiastic and just go as hard as we can as a team. We pitched well, played defense and found a way to get a win."

The Astros led 3-1 before the Reds tied it with consecutive homers by Chris Heisey and Drew Stubbs in the seventh inning.

Michael Bourn gave the Astros an early lead with a two-run single in the second inning and Houston's offense was helped by drawing a season-high nine walks.

"We fought to get back, but it is very difficult to win when you give up nine walks," Reds manager Dusty Baker said. "Three of their four runs were walked."

Pence also had a nice diving catch for the first out in the seventh inning to aid in the victory.

"Everything that he does every day is all out and [he does] everything that he can do to help this ball club win," Houston manager Brad Mills said of Pence.

Wandy Rodriguez tied a season high by allowing 10 hits and gave up three runs with four strikeouts in seven innings. He was replaced by Wilton Lopez, who pitched a perfect eighth before Mark Melancon (3-1) in the ninth.

Mills has been impressed with the work of Melancon, who has been filling in at closer with Brandon Lyon on the disabled list. He has a 1.45 ERA this season.

"He developed into the pitcher that we knew he was capable of being," Mills said.

Pence doubled with two outs in the seventh inning to extend his hitting streak to 15 games. Logan Ondrusek intentionally walked Brett Wallace before walking Chris Johnson to load the bases, but a pop fly by Matt Downs ended the inning.

Nick Masset pitched a scoreless eighth for Cincinnati.

Heisey's pinch-hit homer off Rodriguez bounced off the inside of the pole in left field and got Cincinnati within 3-2 in the seventh inning. Stubbs followed with his shot to right field that tied at 3-all.

Edgar Renteria reached on an error by third baseman Johnson after the second homer and before a single by Brandon Phillips left runners at the corners with two outs. Jonny Gomes grounded into a force out to end the inning with the game tied.

Sam LeCure pitched two scoreless innings after starter Edinson Volquez left before Ondrusek took over for the seventh inning.

Volquez gave up three hits and three runs with five walks in four innings, his shortest outing of the season.

"I've got to find a way to throw strikes," Volquez said. "My breaking ball and my changeup were good today, but I didn't have my fastball."

Joey Votto singled in the sixth inning before Rodriguez struck out Phillips. Gomes singled but Rodriguez retired the next two batters to get out of that inning.

Cincinnati's first run came when Votto tripled and scored on a groundout by Brandon Phillips with no outs in the fourth inning to make it 3-1. Ramon Hernandez singled with two outs but Rodriguez struck out Jay Bruce to escape the inning.

Houston added a run in the third inning when Wallace scored on a sacrifice fly by Downs. Volquez walked Pence before he was out on a force out by Wallace. Johnson followed with a double to left field to send Wallace to third before Downs' sacrifice.

Volquez walked three straight with one out in the second before retiring Rodriguez to set up Bourn's two-out, two-RBI single.

Phillips robbed Johnson of a hit for the second time in the series when he made a leaping, midair catch for the first out in the second inning. On Monday, Phillips made a nifty diving catch that ended in a belly flop.

Game notes
Janish was back in the lineup Wednesday after missing the previous four games with a sprained right ankle. ... Houston OF Jason Michaels, who is on the disabled list with a shoulder injury, could be activated on Friday when Houston opens a series with the Mets.