Francoeur hit a three-run homer in the first inning, a two-run single in the fourth and a two-run shot in the sixth. He came in with four RBI in 10 games.
The Nationals' skid is their longest since moving to Washington in 2005 from Montreal. The last time the franchise lost nine in a row was the final nine games of the 2000 season.
John Smoltz (2-0) pitched six innings and allowed one run and five hits. He walked two and struck out five -- leaving him just 14 strikeouts shy of 3,000.
He earned his 209th career win and 21st against the Montreal-Washington franchise -- most against any opponent.
After a 91-minute rain delay, Francoeur hit a three-run homer to left in the first off John Lannan (0-2) to make it 4-0. Mark Teixeira drove in the Braves' first run with an RBI single.
Francoeur hit a two-run single with the bases loaded in the fourth inning off Lannan and his two-run shot to nearly the same spot in left off Jason Bergmann in the sixth put the Braves ahead 9-1.
Brian McCann, who had three hits, followed Francoeur and hit a home run on the next pitch.