With 87 percent of the precincts counted, Boustany, a heart surgeon who has four terms in the House under his belt representing the 7th District, had 61 percent of the vote to 39 percent for the 3rd District freshman Landry, a former lawman, state lawmaker and Tea Party favorite, Roll Call reported.
The runoff settled the last U.S. House seat race of 2012.
The two were pitted against each other because of redistricting but Boustany got the edge with about three-quarters of his old 7th District included in the new 3rd District, the Washington publication noted. Boustany was the biggest vote-getter in the Nov. 6 election but failed to get the majority needed to win outright.
Landry is one of 13 congressmen to be defeated by a colleague this election cycle, Roll Call said.
"We won. We won big," Boustany spokesman Neal Patel told The (New Orleans) Times-Picayune.
"He rose above the fray -- all those negative attacks were not who he was. He ran a positive campaign and our opponent didn't have anything to run on."
The newspaper said a representative for the Landry campaign could not be reached for comment.