ATLANTA — Drew Brees threw a pair of touchdown passes and the New Orleans Saints overcame a lackluster offensive showing, holding off the Atlanta Falcons 17-13 Thursday night.Brees hooked up with Jimmy Graham on a 44-yard touchdown and Benjamin Watson on a 1-yard scoring play, both in the first half and good enough to give the first-place Saints (9-2) a sweep of their season series with their NFC South rivals. Atlanta (2-9) dropped its fifth straight game, clinched its first losing season since 2008 and was officially eliminated from the division race with five weeks remaining. The Falcons had a chance to pull off the upset, driving to the Saints 29 with less than 3 minutes to go. But New Orleans turned up the pressure on Matt Ryan, Atlanta missed a long field goal, and the Saints ran off all but the last 5 seconds. The Georgia Dome rocked with chants of “Who Dat! Who Dat!” as the final seconds ticked off the clock, the Saints ensuring they will remain alone atop the NFC South and just one game behind Seattle for home-field advantage throughout the NFC playoffs. New Orleans will face the Seahawks on Dec. 2 in what shapes up as one of the biggest games of the year. The Falcons had hoped to salvage some bit of pride in this lost season, driving from their own 9 — actually, the 3 after Ryan was sacked — to the Saints 29. But Ryan was sacked again by Cameron Jordan and hurried into a pair of incompletions. As the crowd groaned, the Falcons surprisingly sent on Matt Bryant to attempt a 52-yard field goal. He knocked one through, but the Saints called timeout just before the snap. After standing around during the commercial break, Bryant’s next try sailed wide of the left upright.