Zuby Ejiofor scored six of his 16 points in overtime for No. 20 St. John’s, which overcame a 16-point second-half deficit to beat Xavier 79-71 on Wednesday night in New York.Kadary Richmond finished with 19 points, seven rebounds, five assists and three steals for St. John’s (17-3, 8-1 Big East), which has won six straight to move into sole possession of first place in the Big East this late in a season for the first time since 1986.Richmond had the steal that led to Ejiofor’s go-ahead basket 59 seconds into the extra session.RJ Luis Jr. and Simeon Wilcher each had 16 points. Ejiofor added eight rebounds for the Red Storm, who were 22 of 27 from the free-throw line.Ryan Conwell scored 21 points while Dailyn Swain had 16 points and Zach Freemantle added 14 points for the Musketeers (12-8, 4-5), who had their three-game winning streak snapped.Xavier went on a 34-18 run bridging the halves to take its biggest lead at 50-34 on by Marcus Foster’s 3-pointer with 17:02 left before St. John’s began inching back.Consecutive baskets by Richmond put St. John’s up 61-60 with 3:41 left. Luis stole the ball from Conwell on the inbounds and hit a layup, after which Conwell drained a game-tying 3-pointer and Freemantle hit the go-ahead, second-chance layup following a steal by Jerome Hunter for a 65-63 Musketeers edge.