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When Brian McCann returned to his locker, Derek Lowe shouted across the room: "Great off day, Mac!"

A great off day, indeed.

McCann came off the bench in the ninth inning to tie it with a pinch-hit, two-out homer, then hit a two-run shot in the 11th to lead the Atlanta Braves past the Houston Astros 3-1 on Tuesday.

"If the game is close, I know I'm the first one off the bench to hit," the All-Star catcher said. "I'm ready for that. I know that's my role when I'm not playing."

The Braves were trailing 1-0 and down to their final strike in the ninth when McCann drove a 1-2 pitch the opposite way, the ball just clearing the wall in left-center.

He stayed in the game behind the plate and, two innings later, ended it with his fourth homer of the season — a towering drive down the right-field line, just inside the foul pole against Jeff Fulchino (0-2).

Cory Gearrin (1-1) escaped a bases-loaded, one-out jam in the top of the 11th, helped by a disputed call, and was rewarded with his first career win.

McCann was taking one of his regularly scheduled days off, but he wound up leading the Braves to their fourth straight win. Mark Melancon blew the save in the ninth, ruining a brilliant performance by Wandy Rodriguez. The Astros starter pitched five-hit ball over eight scoreless innings but the Astros' beleaguered bullpen couldn't hold it.

McCann made sure of that.

"He's clutch," Gearrin said. "He's such a big part of this team."

Brett Wallace broke up a scoreless duel between Rodriguez and Lowe with a seventh-inning homer.

The Braves didn't do much offensively, even with the return of Chipper Jones and Jason Heyward to the lineup.

Jones, who had missed the last two games with a slight meniscus tear in his right knee, moved well at third base but struck out twice in the late innings with runners aboard. Heyward started for the first time in seven games after undergoing an MRI exam on his right shoulder.

The Astros squandered a chance to go ahead in the 11th against Gearrin. Brian Bogusevic, who entered as a defensive replacement in the eighth, reached on a bunt single and stole second. Wallace was walked intentionally, and it looked as though the Astros had loaded the bases when Matt Downs was hit on the left elbow.

But plate umpire Alfonso Marquez ruled immediately that Downs raised his elbow to let the ball strike him. After a brief argument, Downs returned to the box and struck out.

"That was an absolutely brutal call," manager Brad Mills said. "You don't make that call in that situation where he's trying to get out of the way. He was trying to protect himself."

Clint Barmes followed with a walk that did fill the bases, only to have J.R. Towles hit a hard grounder right at shortstop Alex Gonzalez, who started the 6-4-3 double play.

"I felt like struggled in this game more than any other," Gearrin said. "That's how this game is. It gives and it takes away."

Rodriguez had the win snatched away despite his sixth straight start of at least seven innings. He allowing only two runners to get as far as second base.

"I felt great," the left-hander said. "I think the key was location. I had great location and I used all my pitches."

Rodriguez said he didn't lobby for the complete game after throwing 113 pitches. Still, it was a tough way for the last-place Astros to lose for the eighth time in 10 games.

"Oh my gosh, not only for me but for the team, too," Rodriguez said. "Sometimes we play a good game and we lose. That's what happens sometimes."

The Astros' bullpen, which came in with an ERA above 5.00, faltered again. Houston has converted only five of 16 save chances.

Lowe was breezing along until the seventh, when Wallace drove a 3-1 pitch about four rows deep in the left-center seats to put the Astros ahead. The Braves starter went seven innings, allowing five hits, no walks and striking out four.

"Starting pitching has been our strength all year long," Lowe said. "I'm just trying to do my part."Melancon benefited from two stellar defensive plays to start the ninth. Downs made a diving stop at third on Dan Uggla's hard-hit grounder, hopping up in time to make the throw to first. Then Eric Hinske drove one to the wall in right, but Hunter Pence made the catch crashing into the padding.

Finally, McCann hit it where no one could make the catch. Melancon hung a curveball over the plate, and McCann sent it out the opposite way.

"It's what I wanted to throw," Melancon said. "I left it up."

NOTES: NOTES: The Braves said RHP Peter Moylan underwent successful surgery for a bulging disc in his lower back. He's expected to be out two to three months. ... The Braves have to make a roster move before Wednesday's game in Arizona. RHP Julio Teheran will be coming up from Triple-A Gwinnett to make his second career start, filling in for injured Brandon Beachy. ... The Astros optioned LHP Fernando Abad to Oklahoma City and purchased the contract of RHP Fernando Rodriguez from the Triple-A team.