Making his sixth straight opening day start for the Cubs, Zambrano gave up six hits and two walks with one strikeout.
"I left some pitches over the middle," Zambrano said. "When you do that at this level, you're going to get crushed."
Braves center fielder Nate McLouth made running catches of drives hit by Ramirez in the first and Derrek Lee in the fifth. McLouth was credited with a diving catch of a ball hit by Byrd in the left-center gap in the sixth, though a replay showed the ball popped out of McLouth's glove when he hit the ground.
As umpires called out Byrd, McLouth threw the ball back to Escobar, whose throw to first base forced out Ramirez.
Piniella argued the ruling that McLouth made the catch. The umpires huddled but did not overturn the original call.
Escobar had a three-run double, and pinch-hitter Eric Hinske added a run-scoring triple off Jeff Samardzija in the seventh. Samardzija walked three batters in the six-run inning.
Six Chicago pitchers combined for eight walks.
"The thing that was so upsetting was we didn't walk people in spring training," Piniella said. "I complimented our pitchers on that."
Right-hander Takashi Saito and left-handed closer Billy Wagner pitched perfect innings in their Atlanta debuts to end the game.
NOTES: McCann received his 2009 Silver Slugger award before the game. ... New Cubs owner Tom Ricketts and his brother, Todd, attended the game. ... Sean Marshall had five strikeouts in 2 2-3 perfect innings behind Zambrano. ... Zambrano also lasted only 1 1-3 innings against Pittsburgh on Sept. 4, 2006. ... The other Braves to homer in their first plate appearances were Joe Harrington (1895); Johnny Bates (1906) and Jermaine Dye (1996).
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TORONTO (AP) - R.A. Dickey won his second straight start, Edwin Encarnacion hit a tiebreaking, bases-loaded double in the seventh inning, and the Toronto Blue Jays beat the Tampa Bay Rays 7-5 Monday.
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