AP Photo/Joe Raymond

Notre Dame guard Skylar Diggins, right, drives around Saint John's guard Nadirah McKenith as she is picked by Notre Dame forward Ariel Braker during the first half NCAA college basketball game Sunday, Jan. 20, 2013 in South Bend, Ind. (AP Photo/Joe Raymond) (January 20, 2013)

SOUTH BEND (AP) — Skylar Diggins scored 18 points to lead No. 2 Notre Dame to a 74-50 rout of St. John's on Sunday.

The All-American penetrated at will. When she wasn't scoring on fast breaks, she was hitting pull-up jumpers or feeding forward Natalie Achonwa for easy layups.

Achonwa had 16 points and 12 rebounds for her 10th double-double of the season for Notre Dame (16-1, 5-0). She scored eight of Notre Dame's first 12 points, all on layups.

St. John's (9-7, 3-1) was led by Nadirah McKenith with 15 points.

The Irish took a 39-25 halftime lead on a drive through traffic by Diggins as the clock expired.

Notre Dame outrebounded St. John's 48-22 and outscored the Red Storm 38-24 in the paint.