A Rolando McClain interception return has given the Cowboys a 7-0 lead over the Dolphins.
McClain picked off a Ryan Tannehill pass into the flats and returned it 12 yards on the first play of the second quarter.
The Cowboys have mounted one offensive threat but it was ended by a Brent Grimes interception of Tony Romo. Romo has completed 5 of his first 10 passes for 55 yards.