ATLANTA -- Tommy Hanson said he was pitching well enough to win, even when matched against Jeff Samardzija's dominant splitter for the Chicago Cubs.
Then came the seventh inning.
Atlanta's Hanson gave up a tiebreaking three-run double to Luis Valbuena and the Braves fell 4-1 to the Cubs on Monday night.
Chicago has won four straight games and six of seven.
Hanson (9-5) gave up four runs and seven hits in seven innings for his first loss since May 28. He went 4-0 with a 3.13 ERA in June.
"It's frustrating," Hanson said. "It's not like I went out there and got beat up. I felt like I had good stuff and it just came down to that one inning."
Hanson made it through seven innings for only the sixth time in 17 starts but appeared to fade in his final inning.
Bryan LaHair and Steve Clevenger started the seventh with singles, and Darwin Barney walked to load the bases. Valbuena, the No. 8 hitter who began the day with a .226 batting average, then doubled to right field for the 4-1 lead.
"I wanted to throw a back-door slider right there, and it kind of leaked over the middle," Hanson said.
Anthony Rizzo hit Hanson's first pitch of the fourth inning over the wall in left-center for his second homer.
"He guessed right and ambushed me," Hanson said of Rizzo. "It was a fastball down and away, and he hit it out of the park."
Samardzija had a career-high 11 strikeouts.
Samardzija (6-7) yielded one run and four hits in seven innings, rebounding from a rough June. The right-hander was 0-4 with a 12.27 ERA in his previous four starts, allowing a season-high nine runs during a 17-1 loss to the Mets on Wednesday.
"It's about time, you know?" Samardzija said.
"I just thought I took my time from pitch to pitch. I thought I made the right pitch selection based on the previous pitch."
Samardzija began the night with a 5.05 ERA.
Against the Braves, however, he has been sharp. He gave up five hits and one run in seven innings, while striking out seven, in a 5-1 win over the Braves in Chicago on May 7.
"Both times I've faced him, he's had unbelievable stuff," Hanson said. "He throws hard and has that good split and starts throwing those sliders in there. Anytime you're mixing three pitches, it's tough."
Cubs manager Dale Sveum said a key for Samardzija was he allowed "a three-pitch pitcher to be a three-pitch pitcher" by using his slider, splitter and fastball.
The splitter was the most devastating pitch.
"There were a couple times he threw it four or five times in a row," said Braves manager Fredi Gonzalez. "And we had no chance on it. Especially left-handed hitters."
Rizzo, one of the Cubs' top prospects, has two homers in six games and is batting .304 since he was called up from the minors last Tuesday.
"The way we're playing right now is exciting," Samardzija said. "It's solid all around."
Samardzija said it may not be a coincidence that the Cubs' surge has come since Rizzo joined the team.
"It definitely hasn't hurt," Samardzija said. "Rizzo's presence in our lineup has been big -- a big left-handed hitter."
Jeff Russell pitched the ninth for his second save.
Atlanta tied it in the sixth. With two outs, Michael Bourn doubled to left field and scored on Martin Prado's single.
The Braves' only hit through five innings came with two outs in the second, when Dan Uggla, hustling all the way, beat out an infield hit on a grounder to shortstop Starlin Castro.
Andrelton Simmons led off the Atlanta third with a walk, took second on his first career stolen base and advanced to third on a wild pitch by Samardzija. Hanson then struck out and Bourn lined into a double play.
Barney made a diving stop on Simmons' ground ball behind second base and threw him out in the eighth. The second baseman then went the other way to snag a sharply hit grounder by pinch-hitter Eric Hinske for the second out.