Cross set up Jessica Gjertsen's goal in the 22nd minute, netted one of her own in the 29th, then fed Meghan Schnur 61 seconds later as the 23rd-ranked Huskies (14-5-3) advanced to a College Cup semifinal against No. 6 Florida State on Dec. 5 in Cary, N.C.
No. 1 North Carolina and No. 2 UCLA will meet in the other semifinal. The title game is Dec. 7.
Connecticut will be making its seventh final-four appearance.
Gjertsen fired UConn ahead after Cross' run with the ball from the sideline opened space in the BYU box. Cross chipped goalkeeper Ashley Smith from Gjertsen's pass in seven minutes later, and Schnur chipped Smith from Cross' feed in the 29th minute for a 3-0 edge.
The Cougars (16-7-3) got their goal in the 63rd minute, with Jaime Rendich heading home Aleisha Rose's free kick from outside the Connecticut box.
The match likely was the end of Rose's competitive career. The All-American midfielder is a former U.S. women's national team standout who quit the team because she didn't believe it was proper to play on Sundays.
NCAA DIVISION I
Saturday, Nov. 29
Connecticut 3 (Gjertsen 22, Cross 29, Schnur 30) Brigham Young 1 (Rendich 63)
Friday, Nov. 28
North Carolina 3 (O'Reilly 33, Reddick 45, Tarpley 81) Santa Clara 0
Florida 1 (McMillan 88) Florida State 2 (Rowland 57, Ratliff 69)
UCLA 4 (Jones 16, Mora 37, Davis 77, Devine 90) Penn State 0
Friday, Dec. 5 at Cary, N.C.
Florida State (17-7-1) vs. Connecticut (13-5-3), noon EST
North Carolina (25-0-0) vs. UCLA (20-1-3), 2:30 p.m. EST
Sunday, Dec. 7 at Cary, N.C.