The Tar Heels have shut out their last six opponents, not allowing a goal since their Nov. 1 match against N.C. State.
Since then, North Carolina has compiled more than 540 straight scoreless minutes, most of it behind the goalkeeping of backup Kristin DePlatchett.
North Carolina (21-0) blanked UNC-Greensboro 3-0 during Friday's first-round NCAA Tournament match at Fetzer Field.
UNC then shut out Duke 2-0 in Sunday's second-round match. The Tar Heels will play Rutgers in the third round at Fetzer Field at 2 p.m. Saturday.
"Scoring is so variable," UNC coach Anson Dorrance said. "What you can rely on though is your defense playing well.
"I think that's critical to any championship run is to have a great defense because that's something you can bring to any game. You never know if your offense is going to be there."
That was the case during the first 20 minutes of Sunday's match.
Duke (8-10-1), the only team invited to the tournament with a losing record, pressured UNC, forcing several goalie kicks in the game's opening minutes -- this from a Blue Devil team that played
a 150-minute game against Tennessee on Friday night.