ATLANTA — Sean Renfree threw a touchdown pass and led another scoring drive to overshadow the preseason debut of Rex Grossman as the Atlanta Falcons held off the Baltimore Ravens 20-19 on Thursday night in their final preseason game. Renfree made the most of his final bid to open the season as Matt Ryan’s backup. He completed 10 of 15 passes for 75 yards, including a 25-yard touchdown pass to Carlton Mitchell.