The Big 12 champion Lady Bears (33-1) finally put Michigan away by scoring 13 consecutive points in the third quarter. They led 57-41 on a driving layup by Kalani Brown that capped the 4 1/2-minute spurt.
Baylor, the No. 2 seed, takes a 30-game winning streak into its Lexington Regional semifinal game next Friday against Oregon State, which beat the Lady Bears in the Elite Eight two years ago.
Hallie Thome had 22 points, her fourth straight 20-point game for Michigan (23-10). Katelynn Flaherty, Michigan's career scoring leader, had 18 points on six 3-pointers.
All five of Baylor starters scored in double figures, but coach Kim Mulkey had played only six players before clearing the bench with 11.8 seconds left in the game.
It was the fourth straight double-double for Cox, the 6-foot-4 sophomore who had 30 points and 17 rebounds when Baylor opened Friday with a 96-46 win over Grambling State.
Freshman Alexis Morris and Juicy Landrum both had 17 points. Brown, the 6-7 junior who was the Big 12 Player of the year, had 16 points and with eight rebounds. Dekeiya Cohen had 12 points.
There were four ties and four lead changes before Baylor went ahead to stay on the fifth, a layup by Cox that made it 20-19 at the end of the first quarter. That was during a stretch of eight straight points Cox scored for Baylor, including three straight layups in the first quarter before a short bank shot started the second.
The Wolverines were within 44-41 when Thome made a layup with 7:10 left in the third quarter. They didn't score again until Flaherty's 3-pointer with 1:53 left.
Michigan: After three straight WNIT appearances, including an MVP performance as the Wolverines won that championship last year, Flaherty got her only NCAA experience. She had 20 in their win over Northern Colorado on Friday, and leaves Michigan with 2,776 points.
Baylor: The Lady Bears have 14 straight NCAA Tournament games at home, and swept through first- and second-round games at the Ferrell Center for the sixth year in a row. ... The Lady Bears made it to the Elite Eight the last four seasons, but their last Final Four was during their 40-0 national championship season in 2012.
The Lady Bears are headed to Lexington, Kentucky, to play No. 6 seed Oregon State (25-7) on Friday night. In the Elite Eight two years ago, Oregon State beat then top-seeded Baylor 60-57 in Dallas, only about 100 miles from the Waco campus.