The other two interceptions were thrown by rookie free agent Tim Levcik, who replaced Ray Lucas midway through the third quarter.
It was Lucas who led the only scoring drive for the Dolphins, connecting with rookie tight end Randy McMichael for a spectacular 24-yard touchdown on the last play of the first half.
With Lucas scrambling and time running out in the half, McMichael was left wide open at the 15-yard line. After catching the pass, he started racing toward the end zone and leaped from the 5-yard over two defenders and into the end zone as the crowd roared.
But that was about it as far as positive news for the Dolphins.
As if the interceptions weren't bad enough, the Dolphins also were victimized on special teams for the second consecutive game, with Fred McAfee blocking a Mark Royals punt and Sammy Knight returning the loose ball 38 yards for a touchdown.
The Saints followed two of Fiedler's interceptions with scores — a 28-yard field goal by John Carney in the first quarter and a 2-yard touchdown pass from Aaron Brooks to Joe Horn for a 17-0 lead in the second quarter.
New Orleans got the only score of the second half when quarterback Jake Delhomme sneaked in from 1 yard out on the fourth play of the fourth quarter.
The Dolphins drove into New Orleans territory three times in the second half, but one drive ended when Levcik was intercepted by linebacker Travis Carroll and the other two ended with a fourth-down incompletion.