Landry returned shortly from the locker room and coached the rest of the 29-21 Dallas victory.
In the three Dallas victories, it won the turnover battle by 7-1.
Game 5, a 1-0 Dallas victory, had ended in the third overtime on Friday morning.
A Dallas victory would have meant a virtual stranglehold on the series.
The other, a 25-point Dallas victory, occurred last month.
The result was a 26-17 Dallas victory - and probably more.
But there was nothing sneaky about this Dallas victory before 65,099 fans at Texas Stadium.
A Dallas victory in Detroit tonight will tie the 1957-58 Boston Celtics, who began 14-0.
But a Dallas victory tonight would change everyone's tune.
A Dallas victory over the Giants sends the Cowboys into the playoffs.