Jason Sanders kicked a field goal as time expired to give the Dolphins a 22-20 victory over the Cowboys.
Joining Miami in the play-offs are the Detroit Lions who claimed a divisional title for the first time in almost 30 years, while the Cleveland Browns are also nearly there after an impressive win over the Houston Texans.
The Seattle Seahawks and the Green Bay Packers came out on top in wild late finishes to keep their wildcard hopes alive, while the Tampa Bay Buccaneers are one of the form teams in the league after winning four in a row.