LEXINGTON, Ky. — Tahaad Pettiford scored 16 of his 23 points in the second half while Johni Broome scored eight and grabbed 12 rebounds to help No. 1 Auburn hold off No. 9 Creighton for an 82-70 second-round win in the South Region on Saturday night at Rupp Arena.Auburn (30-5), the top overall seed in the tournament, advance to the Sweet 16 and will face No. 5 Michigan, a 91-79 winner over Texas A&M, in the regional semifinal next Friday in Atlanta.Auburn overcame the losses of two starters in the second half to injury as Chad Baker-Mazara limped off after making two free throws with 13:32 left. He returned with a limp and continued to play before leaving with 1:30 remaining.Starting center Dylan Cardwell went down under the Auburn basket grabbing his right hamstring with 7:36 left and did not return.Baker-Mazara had 12 of his 17 points in the second half before his injury.Ryan Kalkbrenner had 18 points and seven boards while Steven Ashworth and Jamiya Neal had 13 points apiece to lead all five starters in double figures for Creighton (25-11). The Bluejays’ bench was outscored 31-10 by Auburn reserves.The injuries were the only factors slowing down Auburn for most of the second half as they knocked down four 3-pointers and shot 60 percent to go on a 10-0 run and build a 68-54 lead with just over six minutes left.