Bartlett went 0-for-6 over the first two games of the series and 3-for-24 over his last six games.
Torii Hunter also had three hits for the winners, who got a serviceable five innings from Boof Bonser, who improves to 5-and-2. The Twins' bullpen worked four scoreless innings, with Joe Nathan pitching the ninth for his 14th save in 15 chances.
Mike Bacsik gave up four runs over five innings and took the loss for Washington, which stranded eleven baserunners. He falls to 1-and-3.
The Twins avoided being swept at home for the first time by a National League team since interleague play began in 1997