Billy Richmond III scored nine of his 16 points in the second half, allowing 10th-seeded Arkansas to withstand a comeback from second-seeded St. John’s and earn a 75-66 victory in Saturday afternoon’s West Region second-round action in Providence, R.I.The Razorbacks (22-13), who are 5-1 in their last six games, advanced to the Sweet 16 for the fourth time in five years despite shooting just 2-of-19 from 3-point range and four players getting into foul trouble.In a legendary coaching matchup with Rick Pitino of St. John’s (31-5), John Calipari earned his 59th all-time NCAA Tournament win — the most among active coaches.Karter Knox (15 points) and Johnell Davis (13 points) were also double-figure scorers for Arkansas, which had a 13-point lead whittled down to two with 4:11 left in regulation.The Razorbacks will face No. 3 Texas Tech, which defeated No. 11 Drake on Saturday, in the Sweet 16.No. 3 Texas Tech 77, No. 11 Drake 64Darrion Williams scored a season-high 28 points and JT Toppin added 25 points and 12 rebounds to help the Red Raiders down the Bulldogs in West Region second-round play at Wichita, Kan.Elijah Hawkins had 16 points and seven assists for Texas Tech (27-8), which advanced to the Sweet 16 for the fourth time in the past seven NCAA Tournaments. Toppin made 11 of 13 field-goal attempts and Williams hit 11 of 18 shots. Texas Tech will face 10th-seeded Arkansas in the Sweet 16.Bennett Stirtz recorded 21 points and eight assists and Daniel Abreu scored 15 points on five 3-pointers for Drake (31-4). Kael Combs added 13 points and Tavion Banks had 11 for the Bulldogs, who set a school record for victories.South RegionNo. 1 Auburn 82, No. 9 Creighton 70Tahaad Pettiford scored 16 of his 23 points in the second half while Johni Broome scored eight and grabbed 12 rebounds to help the Tigers hold off the Bluejays in Lexington, Ky.Auburn (30-5), the top overall seed in the tournament, advances 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.Ryan Kalkbrenner had 18 points and seven boards while Steven Ashworth and Jamiya Neal had 13 points apiece for Creighton (25-11). The Bluejays’ bench was outscored 31-10 by Auburn reserves.No. 5 Michigan 91, No. 4 Texas A&M 79Reserve Roddy Gayle Jr. scored five of his season-high 26 points in a momentum-turning run in the second half, and the Wolverines rallied from down 10 to beat the Aggies in Denver.Vladislav Goldin finished with 23 points and 12 rebounds, Danny Wolf added 14 points, nine rebounds and three blocks, and L.J. Cason scored 11 points for Michigan (27-9)/Reserve Pharrel Payne had a career-high 26 points, Wade Taylor IV contributed 14 before fouling out and Andersson Garcia scored 11 for Texas A&M (23-11).Midwest RegionNo. 1 Houston 81, No. 8 Gonzaga 76L.J. Cryer made six 3-pointers and matched his career high of 30 points as the Cougars earned their sixth straight Sweet 16 berth with a victory over the Bulldogs in Wichita, Kan.Houston’s Ja’Vier Francis blocked the 3-point shot of the Bulldogs’ Khalif Battle with under three seconds left and Houston leading by three. Milos Uzan then sank two free throws with 2.1 seconds left to seal the victory for the Cougars (32-4), who will face No. 4 Purdue in the Sweet 16.