This entry was written by DCist contributor Benjamin Kabak. For seven innings on Sunday, it looked like the Nationals would come away from the weekend with a two-game sweep of the rain-shortened series with Atlanta. But over the space of three batters on Sunday night, Gary Majewski and the game fell apart. In the end, a three-run home run by Braves shortstop Wilson Betemit highlighted a night of futility for the Nats offense. The Nats’…