NEW YORK — Kam Jones scored 28 points, including the go-ahead basket with 1:16 remaining, as No. 25 Marquette rallied for an 89-87 victory over Xavier in the Big East quarterfinals on Thursday afternoon.Chase Ross and Stevie Mitchell added 16 apiece for the fifth-seeded Golden Eagles (23-9), who advanced to the semifinals for the third straight season. David Joplin chipped in 14 as Marquette shot 61.3 percent in the second half and 48.5 percent overall.Ryan Conwell scored a career-high 38 points by hitting 13 of 18 shots and seven 3s, but fourth-seeded Xavier (21-11) saw a seven-game winning streak stopped. Zach Freemantle added 15 and Dailyn Swain 11 as Xavier shot 52.6 percent.Jones made 11 of 22 shots and hit five 3-pointers to help the Golden Eagles move into a semifinal matchup with top-seeded St. John’s. No shot was bigger than the one that gave Marquette the lead for good at 81-80 after it trailed by 14 in the opening minutes of the second half.After Conwell hit a 3 over Ben Gold with 1:36 left, Jones got the ball in the paint. He made a move around Conwell and converted the difficult layup.Marquette followed Jones’ clutch hoop by getting a major defensive stop when Ross stole the ball from Freemantle in the middle of the paint. Jones fell down in the paint but was able to pass to Joplin, who pushed the lead to 84-80 with a 3-pointer from the right side with 26.1 seconds.Xavier was within 84-82 when Swain hit a layup with 26 seconds left. After Gold split two free throws, Conwell sank two at the line with seven seconds left to make it a one-point game.