Dante Fantoni scored the go-ahead goal, his second, to start a 3-0 run and Adam Johnston added the eventual game-winner with 2:52 left as visiting Lehigh upset No. 4 North Carolina, 9-8, Saturday.
The host Tar Heels (4-1) took a 3-2 lead after the first quarter, before the Mountain Hawks (4-1) stepped up in the second to tie the score, 5-5, at halftime.
Fantoni's goal, the only scoring in the third quarter, gave Lehigh the lead as both teams traded three goals each in the fourth quarter.
Joey Sankey led the Heels with three goals.
The Blue Hens, led by Andrew Tanneberger with four goals, outscored Villanova 9-1 in the second and third quarters.
The victory was the Blue Hens' first over Villanova since an 8-4 win March 22, 2008.
No. 3 Cornell 18, Army 7: Steve Mock scored all five of his goals in the second quarter as the Big Red (2-0) took a 6-2 lead and never looked back. All three starting attackmen were credited with six points. Rob Pannell had a goal and five assists for Cornell. The Black Knights fell to 2-3.
No. 6 Massachusetts 12, Brown 7: The visiting Minutemen (4-0) led from start to finish, getting three goals from Anthony Biscardi and Art Kell, at Meister-Kavan Field.
Parker Brown had four goals for the Bears (1-1).
The award is given to one of three Big 10 teams, Penn State, Ohio State and Michigan, for a 2-0 record against the other programs. Penn State beat Michigan, 16-9, on Feb. 18.
After falling behind 2-0 eight minutes into the contest, the Notre Dame held the Dragons (1-3) scoreless for the next 33:27 and went on a 4-0 run with five minutes left in the third quarter.
No. 1 Northwestern 15, Oregon 2: The host Wildcats (4-0) outshot the Ducks (2-3), 35-7, in their home opener.
No. 2 North Carolina 15, No. 8 Penn 7: The host Heels (6-0) stayed perfect as Abbey Friend had four goals and Laura Zimmerman and Emily Garrity each had hat tricks. Caroline Bunting scored twice for the Quakers (1-1).
Kirkland Locey won the opening draw of the second overtime and passed the ball to Bridget Daley on the left side. Daley fed Webster for the game-winner.
Emille Boeri had two goals and two assists for the Cardinal (1-4).
No. 10 Dartmouth 9, Yale 8: Sarah Plumb's sixth goal broke a tie with 2:12 left in the game to lift the host Big Green (2-0, 1-0 Ivy League) over the Bulldogs (1-1, 0-1).