Last series win over Braves: 24th/25th/26th September 2010 at Nats Park - scores W 8-3, L 0-5, W 4-2; pitchers-of-record Zimmermann, Maya, Burnett respectively.
Last series win at Atlanta: 13th/14th/15th September 2010 - scores L 0-4, W 6-0, W 4-2; pitchers-of-record Maya, Hernandez, Lannan respectively.
Last series sweep by Nationals: 1st/2nd/3rd/4th October 2009 at Atlanta - scores 2-1, 6-3, 6-4 (11), 2-1 (15); winning pitchers Clippard, Hernandez, Segovia, Kensing respectively (in the case of the last two named, these would be their only wins ever as Nationals; in Segovia's case, his only win ever in the majors).
Last series sweep by Braves: 25th/26th/27th September 2009 at Nats Park - scores 1-4, 5-11, 3-6 (10); losing pitchers Lannan, Mock, MacDougal respectively.
Last series sweep by Braves at Atlanta: 11th/12th August 2009 - scores 1-8, 2-6; losing pitchers Lannan and Sosa respectively.
Last sweep of 3-or-more-game series by Braves at Atlanta: 10th/11th/12th April 2009 - scores 5-6 (10), 3-5, 5-8; losing pitchers Beimel, Lannan, Olsen respectively.