Bailey, who has missed just once in 28 attempts this season, produced the winning Dallas points for the second straight week and boosted the Cowboys to their fourth straight victory. He was good on an overtime kick Sunday in a win over Washington.
Dallas moved into first place in the NFC East at 7-4, a half game in front of the New York Giants, who will try to draw even with the Cowboys Monday night when they play in New Orleans.
Dallas quarterback Tony Romo threw two touchdown passes, but he was intercepted twice in the first period and Miami's Matt Moore almost led the Dolphins to what would have been their fourth consecutive win. Instead, Miami fell to 3-8.
Moore drove Miami to a go-ahead field goal of 23 yards by Shayne Graham with 7:14 to play and the Cowboys were unable to move the ball on their ensuing possession.
Miami took over at its own 27 with 4:47 remaining, but the Dolphins were forced to punt and Dallas wound up with the ball at its 36 with 2:59 left.
Romo then marched the Cowboys 54 yards in 10 plays, including a critical 23-yard throw to Jason Witten. Running back DeMarco Murray carried the ball five straight times for a total of 27 yards to set up Bailey's winning field goal.
Both of Romo's touchdown passes went to Laurent Robinson – a 5-yarder with 55 seconds left in the first half and an 18-yarder on the first play of the fourth quarter.
Miami's lone touchdown came on a 35-yard throw from Moore to Brandon Marshall in the third period that put the Dolphins in front 16-10. Graham kicked four field goals, but he missed one of 47 yards in the second quarter.
Romo went 22-of-34 for 226 yards. Moore was good on 19-of-32 passes for 288 yards.