You could argue that the Montreal Canadiens game, which the Dallas Stars won going into the Christmas break, was an underperformance. The Stars ultimately took the game, 4-2, but it was a game - Montreal took it to the end, and it could easily have gone the other way.
Now the Stars take on the Nashville Predators, revisiting the start of the season where Dallas took two straight. You could argue that the home and away series win set the tone for the season to date. Now, coming into the second part of the season, Dallas has the opportunity to stamp themselves as Division favorites (both tonight and Thursday nights game in Minnesota).